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13,600 | Assessment of left atrial deformation and synchrony by three-dimensional speckle-tracking echocardiography: comparative studies in healthy subjects and patients with atrial fibrillation. | The aim of this study was to examine whether left atrial (LA) strain and synchrony can be assessed using three-dimensional (3D) speckle-tracking echocardiography (STE) and how 3D STE parameters are modified by atrial fibrillation (AF).</AbstractText>LA peak ventricular systolic longitudinal strain (LSs), circumferential strain (CSs), and area strain (ASs) and LA peak pre-atrial contraction longitudinal strain, circumferential strain (CSa), and area strain were determined using 3D STE, and SDs of times to peaks of regional LA strain were calculated as indices of LA dyssynchrony. Three-dimensional speckle-tracking was able to measure LA strain in 75 of the 77 healthy subjects and in all 47 patients with AF (31 with paroxysmal AF [PAF] and 16 with permanent AF).</AbstractText>The mean time for analysis with 3D STE was 18% shorter than with two-dimensional (2D) STE (P < .05). On 3D STE, values of interobserver and intraobserver variability of LA strain were <10% and <12%, respectively. LSs, CSs, ASs, and 2D STE LSs were reduced in patients with PAF compared with controls, and further reductions of these parameters were observed in patients with permanent AF. SDs of LSs, CSs, and ASs were similarly larger in patients with PAF and in those with permanent AF compared with controls. Patients with PAF showed smaller LA peak pre-atrial contraction longitudinal strain, CSa, and LA peak pre-atrial contraction area strain and larger SDs of CSa and LA peak pre-atrial contraction area strain compared with controls. In multivariate analysis, 2D STE LSs (P = .044), LSs (P = .040), ASs (P = .007), and CSa (P = .020) were independent predictors of PAF.</AbstractText>Three-dimensional speckle-tracking enables the measurement of both LA strain and synchrony with excellent reproducibility. Three-dimensional LA strain appears to be beneficial compared with 2D LA strain for identifying patients with PAF.</AbstractText>Copyright © 2013 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
13,601 | Effect of ranolazine in preventing postoperative atrial fibrillation in patients undergoing coronary revascularization surgery. | <AbstractText Label="BACKGROUND/OBJECTIVE" NlmCategory="OBJECTIVE">Ranolazine is a new anti-ischemic agent approved for chronic angina with additional electrophysiologic properties. The purpose of the present trial was to investigate its effect in preventing postoperative atrial fibrillation (POAF) after on-pump coronary artery bypass graft (CABG) surgery.</AbstractText>In the current prospective, randomized, (1 active: 2 control), single-blind (outcome assessors), single-centre clinical trial we recruited consecutive eligible patients scheduled for elective on-pump CABG. Participants were assigned to receive either oral ranolazine 375 mg twice daily for 3 days prior to surgery and until discharge, or to receive usual care. Patients were monitored for the development of POAF.</AbstractText>We enrolled 102 patients. Significantly lower incidence of POAF was noted in the ranolazine group compared with the control group (3 out of 34 patients, 8.8%, vs 21 out of 68 patients, 30.8%; p< 0.001). Mean values of left atrial diameter and left ventricular ejection fraction between the control and the ranolazine group were not significantly different.</AbstractText>Our findings suggest a protective role of oral ranolazine when administered in a moderate dose preoperatively in patients undergoing on-pump CABG surgery. Future studies based on a wider sample of patients will eventually support our conclusions.</AbstractText> |
13,602 | Long-term results of transcatheter atrial fibrillation ablation in patients with impaired left ventricular systolic function. | Long-term outcome of AF ablation in patients with impaired LVEF is unknown. The aim of this study is to evaluate sinus rhythm (SR) maintenance, clinical status, and echocardiographic parameters over a long-term period following atrial fibrillation (AF) transcatheter ablation in patients with left ventricular ejection fraction (LVEF) <50%.</AbstractText>A total of 196 patients (87.2% males, age 60.5 ± 10.2 years) with LVEF <50% underwent radiofrequency transcatheter ablation for paroxysmal (22.4%) or persistent (77.6%) AF. Patients were followed up for 46.2 (16.4-63.5) months regarding AF recurrences, functional class, and echocardiographic parameters. All patients underwent pulmonary vein isolation, while 167 (85.2%) required additional atrial lesions. Eleven (5.6%) patients suffered procedural complications. During follow-up, 58 (29.6%) patients required repeated ablations. At the follow-up end, 15 (7.7%) patients died, while 74 (37.8%) documented at least one episode of AF, atrial flutter, or atrial ectopic tachycardia. Eighty-three (47.2%) patients maintained antiarrhythmic drugs. During follow-up, NYHA class improved by at least one class more frequently among patients maintaining SR compared to those experiencing relapses (70.6% vs 47.9%, P = 0.003). LVEF showed a broader relative increase in patients maintaining SR (32.7% vs 21.4%; P = 0.047) and mitral regurgitation grading significantly decreased (P <0.001) only within these patients. At multivariable analysis SR maintenance emerged as an independent predictor (odds ratio 4.26, 95% CI 1.69-10.74, P = 0.002) of long-term clinical improvement (reduction in NYHA class ≥ 1 and relative increase in LVEF ≥ 10%).</AbstractText>Although not substantially worse than in patients with preserved LVEF, AF ablation in patients with impaired LVEF is affected by high long-term recurrence rate. Among these patients SR maintenance is associated with greater clinical improvement.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,603 | Ventricular fibrillation induced by spontaneous hypothermia in a patient with early repolarization syndrome. | The early repolarization (ER) pattern on ECG was originally described in the context of hypothermia.</AbstractText>We present the case of a 34-year-old male with cardiac arrest in the context of spontaneous hypothalamic mediated thermal dysregulation after intracranial hemorrhage. Ventricular fibrillation with a marked ER pattern recurred with therapeutic hypothermia. Spontaneous hypothermia due to hypothalamic dysregulation was observed to enhance the amplitude of the ER pattern and was contemporaneous with recurrent ventricular fibrillation during follow-up.</AbstractText>Hypothermia is an important trigger of VF in the setting of early repolarization syndrome, and warrants assessment as an environmental trigger of spontaneous events.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,604 | Recurrent syncope in a hypertensive subject with vascular cognitive impairment and permanent pacemaker. | Syncope following permanent pacemaker (PM) implantation is a nightmare for electrophysiologists. We describe a case of daily recurrent syncope in an 84-year-old man having a dual-chamber pacemaker implanted for complete atrio-ventricular block occurred 4 years before the admission to our department. He had a history of arterial hypertension, parossistic atrial fibrillation, chronic obstructive pulmonary disease, stage-III chronic renal failure, mild vascular cognitive impairment and glaucoma. The initial work-up including electrocardiogram (ECG), repeated PM interrogations, Holter electrocardiogram, blood pressure measurement in orthostatic position, complete blood count, serum glycaemia, electrolytes and thyroid function tests showed normal findings. Syncope occurred in lying position and during 90° left clockwise neck rotation and was associated to pallor, sweating, tonic-clonic seizures and transient self-limited loss of consciousness lasting a few seconds. Electroencephalogram was normal. During continuous ECG monitoring, the right rotation of the head determined a ventricular asystolic pause lasting 9 seconds associated with loss of consciousness. Restoration of sinus rhythm was observed after bringing back the head in axis. The PM interrogation, performed during pacing failure, recorded low impedance of bipolar ventricular lead, suggesting a damage in lead insulation. It is likely that lead movements during clockwise neck rotation produced an intermittent short circuit that prevented sufficient energy delivery to the myocardium with a consequence of sudden loss of capture. |
13,605 | In-hospital mortality and long-term survival after coronary artery bypass surgery in young patients. | Coronary artery bypass graft (CABG) is performed for symptomatic and prognostic reasons. We aimed to determine the factors that contribute to in-hospital mortality and long-term survival in young patients (aged less than 65) undergoing CABG.</AbstractText>A prospective database was retrospectively analysed and cross-correlated with the United Kingdom's Strategic Tracing Service to evaluate survival in patients under the age of 65, following isolated primary CABG. Univariate-, multivariate logistic with Cox regression- and neural network analyses were performed.</AbstractText>Patients under the age of 65, who had undergone isolated CABG between April 1997 and March 2010 were studied;n = 5967. In-hospital mortality was 1.1% and long-term mortality was 13.5%; median follow-up 7.9 years. Multivariate analysis demonstrated that atrial fibrillation, 'urgent' operation status, postoperative creatinine kinase (CKMB), moderate or poor left ventricular (LV) function, and female sex were significant factors predicting in-hospital mortality. Cox regression demonstrated that age, diabetes (oral and insulin controlled), moderate and poor LV function, cerebrovascular disease, dialysis, left internal mammary artery (LIMA) usage, postoperative CKMB, atrial fibrillation, 'urgent' operation status, and peripheral vascular disease were significant factors determining long-term survival. Radial artery use, off-pump surgery, composite arterial grating and graft number had no effect on in-hospital mortality or long-term survival. Neural network analysis confirmed the factors identified by logistic and Cox multivariate analysis.</AbstractText>The risk factors for in-hospital mortality in patients under the age of 65 include postoperative CKMB, urgent operation status, LV function, female sex and atrial fibrillation. Significant factors determining long-term survival in the under-65 age group include age, atrial fibrillation, diabetes (diet and insulin controlled), LV function, cerebrovascular disease, dialysis, LIMA usage, 'urgent' operation status, CKMB and peripheral vascular disease.</AbstractText> |
13,606 | Is heart failure guideline adherence being underestimated? The impact of therapeutic contraindications. | Several studies based on claims data have reported underutilization of evidence-based heart failure (HF) therapies. The degree to which these estimates fail to account for therapeutic contraindications is unclear.</AbstractText>We identified patients with HF and left ventricular ejection fraction ≤45% seen between January 1, 2010, and July 1, 2010, at a tertiary care Veterans Affairs Medical Center. Medical records were abstracted to evaluate utilization of and contraindications to β-blocker, angiotensin-converting enzyme inhibitor, aldosterone antagonist, anticoagulation for atrial fibrillation, implantable cardioverter-defibrillator, and cardiac resynchronization therapies.</AbstractText>Of the 178 patients with HF and an ejection fraction ≤45%, 78 (44%) received every guideline-recommended therapy. After accounting for medical contraindications, 77 (72%) of 107 patients received every guideline-recommended therapy. Adherence to recommendations for β-blocker (98%), angiotensin-converting enzyme inhibitor/angiotensin blocker (95%), and anticoagulation (97%) were better than adherence to implantable cardioverter-defibrillator (82%), cardiac resynchronization therapy (59%), or aldosterone antagonist (51%) recommendations. In adjusted analysis, lower New York Heart Association functional class and care by a cardiologist were associated with improved guideline adherence (P < .001).</AbstractText>Many patients with HF have therapeutic contraindications, and a failure to account for these may lead to a large underestimation of the true guideline adherence rates.</AbstractText>Copyright © 2012 Mosby, Inc. All rights reserved.</CopyrightInformation> |
13,607 | Impaired left ventricular function as a predictive factor for mid-term survival in octogenarians after primary coronary artery bypass surgery. | The impact of preoperative impaired left ventricular ejection fraction (EF) in octogenarians following coronary bypass surgery on short-term survival was evaluated in this study.</AbstractText>A total of 147 octogenarians (mean age 82.1 ± 1.9 years) with coronary artery diseases underwent elective coronary artery bypass graft between January 2000 and December 2009. Patients were stratified into: Group I (n = 59) with EF >50%, Group II (n = 59) with 50% > EF >30% and in Group III (n = 29) with 30% > EF.</AbstractText>There was no difference among the three groups regarding incidence of COPD, renal failure, congestive heart failure, diabetes, and preoperative cerebrovascular events. Postoperative atrial fibrillation was the sole independent predictive factor for in-hospital mortality (odds ratio (OR), 18.1); this was 8.5% in Group I, 15.3% in Group II and 10.3% in Group III. Independent predictive factors for mortality during follow up were: decrease of EF during follow-up for more that 5% (OR, 5.2), usage of left internal mammary artery as free graft (OR, 18.1), and EF in follow-up lower than 40% (OR, 4.8).</AbstractText>The results herein suggest acceptable in-hospital as well short-term mortality in octogenarians with impaired EF following coronary artery bypass grafting (CABG) and are comparable to recent literature where the mortality of younger patients was up to 15% and short-term mortality up to 40%, respectively. Accordingly, we can also state that in an octogenarian cohort with impaired EF, CABG is a viable treatment with acceptable mortality.</AbstractText> |
13,608 | The effect of acute versus delayed remote ischemic preconditioning on reperfusion induced ventricular arrhythmias. | The effect of remote ischemic preconditioning (RIPC) on arrhythmias in in vivo models is unknown. Our purpose was to determine effects of both acute and delayed RIPC on arrhythmias.</AbstractText>In the acute protocol anesthetized open chest rats were exposed to 5 minutes of proximal left coronary artery occlusion (CAO) and 10 minutes of reperfusion. Rats were either untreated (ischemia/reperfusion, IR group, n = 17) or received RIPC (n = 14) with 5 minutes bilateral femoral occlusions followed by 5 minutes of reperfusion times 3, started 30 minutes before CAO. At reperfusion, onset of ventricular tachycardia (VT) was delayed in RIPC group (25.7 seconds) versus IR (8.8 seconds; P = 0.04). Number of episodes of VT was 17.0 in IR versus 3.0 in the RIPC group (P = 0.01) and duration of VT was 54.1 seconds in IR versus 4.9 seconds in RIPC (P = 0.019). Number of ventricular premature complexes (VPC) was 26.0 in IR and 10.0 in RIPC rats (P = 0.04). Levels of reperfusion injury salvage kinases (RISK), that is, phospho-Akt and phospho-p70S6 in the risk area of IR and RIPC hearts were similarly higher compared to the nonischemic areas both at 1 and 10 minutes into reperfusion. Delayed RIPC was induced on day 1 and on day 2, myocardial IR was induced. Delayed RIPC did not affect VT or VPC.</AbstractText>Acute RIPC of the lower limbs induced a powerful delay in/and reduction in IR induced ventricular arrhythmias, but without evoking the RISK pathway; a late protective phase of RIPC on arrhythmias did not occur.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,609 | Investigation into causes of abnormal cerebral MRI findings following PVAC duty-cycled, phased RF ablation of atrial fibrillation. | Left atrial catheter ablation of the pulmonary veins (PVs) is an established option for patients with atrial fibrillation (AF). Asymptomatic cerebral emboli (ACE) detected by diffusion weighted MRI (DW-MRI) following AF ablation has been reported at varying rates. This variability may be linked to procedural variables and demographic risk factors. Animal studies with the multielectrode pulmonary vein ablation catheter (PVAC) have identified potential sources of emboli, including air introduced during PVAC introduction, inadequate anticoagulation, and high current densities when the distal (E1) and proximal (E10) electrodes are in contact. We sought to evaluate the incidence, size, and number of DW-MRI findings with procedural modifications that potentially reduce the embolic load.</AbstractText>Thirty-seven AF patients (59 ± 10 years, 73% male, all with paroxysmal AF, left atrial [LA] diameter 44 ± 7 mm, left ventricular ejection fraction 57 ± 7%) underwent MRI sequences preceding ablation, within 24 hours postablation, and at 4-6 weeks. During the procedure all patients were on uninterrupted phenprocoumon, an attempted activated clotting time (ACT) level >300 seconds, had the PVAC introduced under saline, and antral ablation was started with a 2:1 bipolar/unipolar mode. Files from the ablation unit (GENius v14.4) were retrospectively analyzed to determine the relationship between E1 and E10 in close proximity and DW-MRI findings.</AbstractText>Post procedure, 10/37 patients (27%) were positive for new DWI cerebral lesions. Nine of 10 patients had a single lesion, and 1/10 patient had 2 lesions. Average lesion size was 3.1 ± 3.9 mm (2-14 mm). One of 10 (10%) had lesions at MRI follow-up. No neurological symptoms were observed. Eighteen of 37 (49%) of procedures had evidence of E1/E10 interaction. In the subgroup of patients with and without E1 and E10 in close proximity, the DW-MRI rate was 8/18 (44%) and 2/19 (11%), respectively (P = 0.029).</AbstractText>The source of positive DW-MRI findings in LA ablation involves several factors. Controlling anticoagulation and careful sheath management helps to reduce the number and size of DW-MRI lesions. With the PVAC catheter, an ablation with the E1 and E10 in close proximity increases the risk of a DW-MRI finding. In the future, electrodes E1 and E10 should be kept apart to help reduce the incidence of acute ACE.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,610 | Total beta-adrenoceptor knockout slows conduction and reduces inducible arrhythmias in the mouse heart. | Beta-adrenoceptors (β-AR) play an important role in the neurohumoral regulation of cardiac function. Three β-AR subtypes (β(1), β(2), β(3)) have been described so far. Total deficiency of these adrenoceptors (TKO) results in cardiac hypotrophy and negative inotropy. TKO represents a unique mouse model mimicking total unselective medical β-blocker therapy in men. Electrophysiological characteristics of TKO have not yet been investigated in an animal model.</AbstractText>In vivo electrophysiological studies using right heart catheterisation were performed in 10 TKO mice and 10 129SV wild type control mice (WT) at the age of 15 weeks. Standard surface ECG, intracardiac and electrophysiological parameters, and arrhythmia inducibility were analyzed.</AbstractText>The surface ECG of TKO mice revealed a reduced heart rate (359.2±20.9 bpm vs. 461.1±33.3 bpm; p<0.001), prolonged P wave (17.5±3.0 ms vs. 15.1±1.2 ms; p = 0.019) and PQ time (40.8±2.4 ms vs. 37.3±3.0 ms; p = 0.013) compared to WT. Intracardiac ECG showed a significantly prolonged infra-Hisian conductance (HV-interval: 12.9±1.4 ms vs. 6.8±1.0 ms; p<0.001). Functional testing showed prolonged atrial and ventricular refractory periods in TKO (40.5±15.5 ms vs. 21.3±5.8 ms; p = 0.004; and 41.0±9.7 ms vs. 28.3±6.6 ms; p = 0.004, respectively). In TKO both the probability of induction of atrial fibrillation (12% vs. 24%; p<0.001) and of ventricular tachycardias (0% vs. 26%; p<0.001) were significantly reduced.</AbstractText>TKO results in significant prolongations of cardiac conduction times and refractory periods. This was accompanied by a highly significant reduction of atrial and ventricular arrhythmias. Our finding confirms the importance of β-AR in arrhythmogenesis and the potential role of unspecific beta-receptor-blockade as therapeutic target.</AbstractText> |
13,611 | [Use of cardiac MRI in the field of electrophysiology. Present status and future aspects]. | In recent years, ablation therapy has become the first-line treatment of modern electrophysiology in patients with cardiac arrhythmias. Today, cardiac magnetic resonance imaging (cMRI) is an important supportive imaging technique in the implementation of complex electrophysiological investigations and ablation therapy. In clinical routine, cMRI is used not only to generate accurate three-dimensional (3D) models of cavities of the heart but also for visualization of complex anatomical structures. The development of cMRI makes it possible to detect the underlying substrate of complex arrhythmias such as myocardial scar in patients with ventricular tachycardia or the structural remodeling of the left atrium in patients with atrial fibrillation. The opportunity of fusion of the different imaging modalities (e.g., fluoroscopy, cMRI) has become essential for the planning and the implementation of a safe ablation therapy. The possibility of direct visualization of induced lesions using cMRI after and in the long term after ablation can predict the success of therapy and detects potential complications. The continuous research in the field of cMRI and the development of MRI-compatible pacing and ablation catheters provided the basics for performing electrophysiological treatment in humans directly inside the MRI. The implementation of ablation using exact visualization of the anatomical substrate, precise catheter navigation and real-time visualization of lesions in cMRI promises to improve success rates and the safety of complex ablation treatment and may revolutionize electrophysiology in the future. |
13,612 | A classification scheme for ventricular arrhythmias using wavelets analysis. | Identification and classification of ventricular arrhythmias such as rhythmic ventricular tachycardia (VT) and disorganized ventricular fibrillation (VF) are vital tasks in guiding implantable devices to deliver appropriate therapy in preventing sudden cardiac deaths. Recent studies have shown VF can exhibit strong regional organizations, which makes the overlap zone between the fast paced rhythmic VT and VF even more ambiguous. Considering that implantable cardioverter-defibrillator (ICD) are primarily rate dependent detectors of arrhythmias and that there may be patients who suffer from arrhythmias that fall in the overlap zone, it is essential to identify the degree of affinity of the arrhythmia toward VT or organized/disorganized VF. The method proposed in this work better categorizes the overlap zone using Wavelet analysis of surface ECGs. Sixty-three surface ECG signal segments from the MIT-BIH database were used to classify between VT, organized VF (OVF), and disorganized VF (DVF). A two-level binary classifier was used to first extract VT with an overall accuracy of 93.7% and then the separation between OVF and DVF with an accuracy of 80.0%. The proposed approach could assist clinicians to provide optimal therapeutic solutions for patients in the overlap zone of VT and VF. |
13,613 | Idiopathic ventricular fibrillation, early repolarization and other J wave-related ventricular fibrillation syndromes: from an electrocardiographic enigma to an electrophysiologic dogma. | Current clinical and experimental data demonstrate that the electrocardiographic J wave plays a critical role in the pathogenesis of ventricular fibrillation (VF) in patients with Brugada syndrome (BS) and early repolarization (ER) syndrome (ERS). This has generated renewed interest in the presence of J waves and ERS in the general population, yet the identification of high-risk ECG markers and the risk stratification of subjects with ERS remain to be established. More recently, this concept has been expanded to VF mechanisms in patients with structural heart diseases. Some of the fatal arrhythmias in the setting of acute myocardial ischemia or infarction may share a similar, J wave-related electrophysiologic process. In canine arterially perfused wedge preparations, the occurrence of J wave-related arrhythmias is mediated by phase 2 reentry. The stability of the action potential (AP) dome in the ventricular epicardium is dependent on the prominence of the AP phase 1 notch. The ability to maintain the AP dome depends on a delicate balance between inward and outward ionic currents during depolarization and the early phase of repolarization. Outward shifts of the balance and inability to maintain the AP dome result in marked dispersion of repolarization and vulnerability to VF. This review describes the electrocardiographic and clinical features of the J waves in idiopathic VF and other structural heart diseases. |
13,614 | Conduction slowing contributes to spontaneous ventricular arrhythmias in intrinsically active murine RyR2-P2328S hearts. | The familial condition catecholaminergic polymorphic ventricular tachycardia (CPVT) is characterized by episodic bidirectional ventricular tachycardia (BVT), polymorphic ventricular tachycardia (PVT), and ventricular fibrillation following adrenergic challenge. It is associated with mutations involving the cardiac ryanodine receptor (RyR2).</AbstractText>We explored for a slowing of myocardial conduction that could potentially result in a substrate for the spontaneous arrhythmogenesis that was observed following introduction of isoproterenol and caffeine in intrinsically beating murine RyR2-P2328S hearts. Such pharmacological challenge increased the number of arrhythmic episodes in electrocardiographic recordings from intact anesthetized mice, with the greatest effects in the homozygote RyR2(S/S). Arrhythmias took the form of bigeminy, BVT, monomorphic ventricular tachycardia, and PVT, as found in human CPVT. Ventricular epicardial conduction velocities (CVs) measured using multielectrode array recordings and maximum action potential upstroke rates, (dV/dt)(max), measured using intracellular microelectrodes were indistinguishable in untreated wild-type (WT) and RyR2(S/S). Pharmacological challenge of RyR2(S/S), but not WT hearts, then reduced CV and (dV/dt)(max) and also revealed a strongly arrhythmic phenotype. There was no evidence of gross structural or fibrotic changes in either RyR2(+/S) or RyR2(S/S) hearts on light microscopy.</AbstractText>We associate altered ventricular myocardial CV potentially resulting in arrhythmogenic substrate with arrhythmic properties associated with genetic RyR2 alterations for the first time.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,615 | Clinical characteristics, mortality, cardiac hospitalization, and ventricular arrhythmias in patients undergoing CRT-D implantation: results of the ACTION-HF study. | The characteristics and outcomes of patients who undergo cardiac resynchronization therapy (CRT) device implantation in current clinical practice may differ from those of reference trial populations. Study objectives were to assess 2-year outcomes in a population implanted with a CRT plus defibrillator device in accordance with the standard of care and to evaluate any independent association between clinical variables and outcome.</AbstractText>A total of 406 patients enrolled at 35 centers in Italy were followed up prospectively for 2 years. All patient management decisions were left to the treating physician's discretion, in accordance with clinical practice. ACTION-HF patients had a better baseline clinical status than patients enrolled in the COMPANION study: shorter HF history (1 vs 3.5 years, P < 0.01), less advanced NYHA functional class (III-IV: 73% vs 100%, P < 0.01), higher LVEF (26% vs 21%, P < 0.01), higher SBP (122 vs 112 mmHg, P < 0.01), and less diabetes (27% vs 41%, P < 0.01). This status was reflected in lower mortality (11.5% vs 26%) and a lower incidence of appropriate ICD shocks (12.1% vs 19.3%). AF history was an independent predictor of the combination of all-cause mortality and cardiac-cause hospitalization (HR: 3.31; P < 0.001). Recurrent or new atrial arrhythmias were independently associated with the development of ventricular arrhythmias (HR: 3.4; P < 0.001).</AbstractText>This population appears clinically less compromised and had a lower incidence of adverse clinical outcomes than those of reference trials. However, we recorded a substantial burden of atrial arrhythmias, which was independently associated with a higher incidence of ventricular arrhythmias.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,616 | [Age-related peculiarities and determinating factors of atrial fibrillation]. | The principal aim of the study was to investigate the causes and clinical features of atrial fibrillation (AF) in patients of two age groups--(1) 40-59 years and (2) 60 and elder. 454 male and female patients of the cardiology department were studied. This article discusses recent concepts of the mutual influence of AF and associated clinical cardiovascular conditions and their complications. The duration and degree of correction of cardiovascular pathology and its correlation with the incidence of AF are evaluated. |
13,617 | Global Psychological Distress and Risk of Atrial Fibrillation Among Women: The Women's Health Study. | Symptoms of psychological distress and depression have been associated with risk of ventricular arrhythmias and sudden cardiac death. Their relationship with atrial arrhythmias, however, is less well studied.</AbstractText>We sought to assess the long-term relations between psychological distress and risk of atrial fibrillation (AF) in the Women's Health Study of female health professionals. We measured psychological symptoms with the Mental Health Inventory-5. Incident AF was assessed annually and verified through medical records. Among 30 746 women without history of cardiovascular disease or AF, 771 cases of AF occurred during a median follow-up of 125 months (interquartile range, 117-130 months). Global psychological distress was not associated with AF risk in age-stratified (P=0.61 for linear trend) or multivariable proportional-hazards models that included antidepressant use (P=0.34). A proxy measure for depression, consisting of Mental Health Inventory-5 score <53, antidepressant use, or both, was also not associated with AF risk in multivariable models (hazard ratio=0.99; 95% confidence interval, 0.78-1.25; P=0.93). In post hoc analyses of individual symptoms from the Mental Health Inventory-5, positive affect, "feeling happy some/a good bit of the time," was associated with reduced risk of AF (hazard ratio=0.69; 95% confidence interval, 0.49-0.99; P=0.04); other depressive and anxious symptoms were not.</AbstractText>In this prospective study of women without known cardiovascular disease, global psychological distress and specific depressive symptoms were unrelated to AF risk. (J Am Heart Assoc. 2012;1:e001107 doi: 10.1161/JAHA.112.001107.).</AbstractText> |
13,618 | Incremental Reduction in Risk of Death Associated With Use of Guideline-Recommended Therapies in Patients With Heart Failure: A Nested Case-Control Analysis of IMPROVE HF. | Several therapies are guideline-recommended to reduce mortality in patients with heart failure (HF) and reduced left ventricular ejection fraction, but the incremental clinical effectiveness of these therapies has not been well studied. We aimed to evaluate the individual and incremental benefits of guideline-recommended HF therapies associated with 24-month survival.</AbstractText>We performed a nested case-control study of HF patients enrolled in IMPROVE HF. Cases were patients who died within 24 months and controls were patients who survived to 24 months, propensity-matched 1:2 for multiple prognostic variables. Logistic regression was performed, and the attributable mortality risk from incomplete application of each evidence-based therapy among eligible patients was calculated. A total of 1376 cases and 2752 matched controls were identified. β-Blocker and cardiac resynchronization therapy were associated with the greatest 24-month survival benefit (adjusted odds ratio for death 0.42, 95% confidence interval (CI), 0.34-0.52; and 0.44, 95% CI, 0.29-0.67, respectively). Angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, implantable cardioverter-defibrillators, anticoagulation for atrial fibrillation, and HF education were also associated with benefit, whereas aldosterone antagonist use was not. Incremental benefits were observed with each successive therapy, plateauing once any 4 to 5 therapies were provided (adjusted odds ratio 0.31, 95% CI, 0.23-0.42 for 5 or more versus 0/1, P<0.0001).</AbstractText>Individual, with a single exception, and incremental use of guideline-recommended therapies was associated with survival benefit, with a potential plateau at 4 to 5 therapies. These data provide further rationale to implement guideline-recommended HF therapies in the absence of contraindications to patients with HF and reduced left ventricular ejection fraction. (J Am Heart Assoc. 2012;1:16-26.).</AbstractText> |
13,619 | Sleep-disordered breathing in patients with implantable cardioverter-defibrillator. | To assess the prognostic significance of screening for sleep-disordered breathing in patients with implantable cardioverter-defibrillator (ICD) with regard to appropriate ICD therapy and total mortality.</AbstractText>Overnight sleep studies were performed in 204 ICD recipients not known to have sleep apnoea and with no history of daytime sleepiness. Sleep-disordered breathing was diagnosed in the presence of an apnoea-hypopnea index of five or more events per hour. Seventy patients (34%) had no sleep apnoea, 105 patients (51%) had central sleep apnoea, and 29 patients (14%) had obstructive sleep apnoea. During 38 ± 26 months follow-up, 80 patients (39%) received appropriate ICD therapy for ventricular tachycardia (VT) or ventricular fibrillation (VF), and 54 patients (26%) died. On multivariate Cox regression analysis, age, left ventricular (LV) end-diastolic diameter, secondary prevention ICD indication, use of diuretics, and absence of aldosterone antagonist therapy but not sleep apnoea were associated with appropriate ICD therapy for VT or VF. In addition, multivariate Cox analysis identified age and LV ejection fraction but not sleep apnoea as predictors of total mortality.</AbstractText>Undiagnosed sleep-disordered breathing is common in ICD recipients. The presence and severity of previously unknown sleep apnoea in ICD recipients, however, does not appear to be an independent predictor of appropriate ICD therapy or morality during follow-up.</AbstractText> |
13,620 | Atrial fibrillation with wide QRS tachycardia and undiagnosed Wolff-Parkinson-White syndrome: diagnostic and therapeutic dilemmas in a pediatric patient. | A 10-year-old girl presented to the emergency department of a regional hospital with 1 episode of generalized tonic-clonic seizures. Postictal monitoring followed by a 12-lead electrocardiogram showed fast atrial fibrillation with intermittent wide QRS regular tachycardia. Immediately following this, her rhythm changed to wide QRS irregular tachycardia without hemodynamic compromise. She was suspected to have ventricular tachycardia and was treated with intravenous amiodarone with cardioversion to sinus rhythm. Subsequent electrocardiogram in sinus rhythm showed typical features of manifest Wolff-Parkinson-White (WPW) accessory pathway. This case illustrates the diagnostic and therapeutic dilemmas in patients with atrial fibrillation, wide QRS tachycardia, and undiagnosed WPW syndrome with antidromic conduction of atrial arrhythmias through the accessory pathway. Furthermore, this case demonstrates that undiagnosed wide QRS tachycardias need to be treated with drugs acting on the accessory pathway, thus keeping in mind underlying WPW syndrome as a possibility to avoid potentially catastrophic events. |
13,621 | Electrophysiological effects of acute atrial stretch on persistent atrial fibrillation in patients undergoing open heart surgery. | The electrophysiologic effects of acute atrial dilatation and dedilatation in humans with chronic atrial fibrillation remains to be elucidated.</AbstractText>To study the electrophysiological effects of acute atrial dedilatation and subsequent dilatation in patients with long-standing persistent atrial fibrillation (AF) with structural heart disease undergoing elective cardiac surgery.</AbstractText>Nine patients were studied. Mean age was 71 ± 10 years, and left ventricular ejection was 46% ± 6%. Patients had at least moderate mitral valve regurgitation and dilated atria. After sternotomy and during extracorporal circulation, mapping was performed on the beating heart with 2 multielectrode arrays (60 electrodes each, interelectrode distance 1.5 mm) positioned on the lateral wall of the right atrium (RA) and left atrium (LA). Atrial pressure and size were altered by modifying extracorporal circulation. AF electrograms were recorded at baseline after dedilation and after dilatation of the atria afterward.</AbstractText>At baseline, the median AF cycle length (mAFCL) was 184 ± 27 ms in the RA and 180 ± 17 ms in the LA. After dedilatation, the mAFCL shortened significantly to 168 ± 13 ms in the RA and to 168 ± 20 ms in the LA. Dilatation lengthened mAFCL significantly to 189 ± 17 ms in the RA and to 185 ± 23 ms in the LA. Conduction block (CB) at baseline was 14.3% ± 3.6% in the RA and 17.3% ± 5.5% in the LA. CB decreased significantly with dedilatation to 7.4% ± 2.9% in the RA and to 7.9% ± 6.3% in the LA. CB increased significantly with dilatation afterward to 15.0% ± 8.3% in the RA and to 18.5% ± 16.0% in the LA.</AbstractText>Acute dedilatation of the atria in patients with long-standing persistent AF causes a decrease in the mAFCL in both atria. Subsequent dilatation increased the mAFCL. The amount of CB decreased with dedilatation and increased with dilatation afterward in both atria.</AbstractText>Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,622 | Blunted proarrhythmic effect of nicorandil in a Langendorff-perfused phase-2 myocardial infarction rabbit model. | Nicorandil (a K(ATP) opener) administration is reported to reduce ventricular arrhythmias 4.8 ± 2.2 hours after myocardial infarction (MI). The electrophysiological changes and the effects on dynamic factors and dynamically induced spatially discordant alternans by nicorandil during phase-2 MI are unclear.</AbstractText>Simultaneous voltage and intracellular Ca(2+) (Ca(i)) optical mapping was performed in nine Langendorff-perfused hearts 4-5 hours after coronary artery ligation and nine control hearts. Action potential duration (APD) restitution was constructed and arrhythmogenic alternans was induced by dynamic pacing. Western blot studies (Kir6.1 and Kir6.2) were performed in six more hearts for both groups. Nicorandil (100 μM) was administered after baseline studies.</AbstractText>Phase-2 MI hearts showed longer APD, slower conduction velocity (CV), and higher ventricular fibrillation (VF) inducibility than the control hearts. Nicorandil shortened and restored APD without significant arrhythmogenic effects, and also increased the rate of Ca(i) reuptake and flattened CV restitution to suppress spatially discordant alternans, which might account for a tendency toward higher VF threshold with nicorandil infusion in phase-2 MI hearts. Immunoblotting studies showed significant down-regulation of K(ATP) protein expression, which was functionally correlated to the blunted APD shortening response to nicorandil.</AbstractText>K(ATP) expression is down-regulated in phase-2 MI hearts. Nicorandil restores APD, increases the rate of Ca(i) reuptake, and flattens CV restitution to suppress spatially discordant alternans induction, which ameliorates its proarrhythmic effects during phase-2 MI.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,623 | Arrhythmogenic risk of pulmonary artery catheterisation in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation. | Many clinicians consider severe aortic stenosis to be a contraindication to pulmonary artery catheterisation, except during open heart surgery with cardiopulmonary bypass. This is due to the perceived high risk of arrhythmia, although the true incidence of ventricular tachycardia and fibrillation remains unclear. We conducted a retrospective study to estimate the incidence of severe arrhythmias during pulmonary artery catheterisation in 380 patients with severe aortic stenosis scheduled for transcatheter aortic valve implantation. Ventricular fibrillation was seen in only one patient (0.26%), and this was successfully terminated by external defibrillation. No episodes of ventricular tachycardia were recorded and there were also no arrhythmias during removal of the catheter. We have therefore concluded that pulmonary artery catheterisation in patients with severe aortic stenosis is not associated with a high incidence of ventricular fibrillation or tachycardia, allowing pulmonary artery pressure monitoring to be performed relatively safely in such patients. |
13,624 | Predictors of high defibrillation threshold in the modern era. | High defibrillation threshold (DFT) is a clinical problem in 1-8% of implantable cardioverter-defibrillator implants. Some clinicians and investigators question whether the benefits of routine DFT testing outweigh the risks. Identification of the predictors of elevated DFT may allow selective application of DFT testing. However, the clinical characteristics of patients with high DFT in the modern era have not been well-defined.</AbstractText>All patients who underwent DFT testing in our institution during an 8-year period were reviewed for this retrospective study. High DFT was defined as less than a 10-J safety margin on initial testing. For each case, the two cases preceding and two cases following by the same implanter were selected as controls.</AbstractText>Of the 2,138 patients who underwent DFT testing, 48 (2.2%) met criteria for high DFT. Compared to 192 control patients, patients with high DFT were more likely to be younger (P = 0.004), have nonischemic cardiomyopathy (P = 0.036), have a longer QRS interval (P = 0.026), and have a left ventricular ejection fraction (LVEF) ≤ 0.25 (P = 0.013). On multivariate analysis, only younger age (P = 0.016) and LVEF ≤ 0.25 (P = 0.010) remained statistically significant predictors of elevated DFT.</AbstractText>High DFT was identified in 2.2% of ICD implants in our institution in recent years. Although younger age and depressed LVEF predicts this problem, elevated DFT occurred in patients of all ages and ejection fractions. Elimination of routine DFT testing appears to be premature given the prevalence and unpredictability of elevated DFT.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,625 | Prolonged atrial effective refractory periods in atrial fibrillation patients associated with structural heart disease or sinus node dysfunction compared with lone atrial fibrillation. | Atrial fibrillation (AF) is commonly associated with structural heart disease (SHD) or sinus node dysfunction (SND). We hypothesized that regional atrial effective refractory period (ERP) is different in patients with SHD/SND from lone AF.</AbstractText>We included 648 patients with AF (age, 56.0 ± 11.0 years; male, 77.3%; paroxysmal AF [PAF], 67.9%; persistent AF [PeAF], 32.1%) who underwent radiofrequency catheter ablation (RFCA), and compared the clinical characteristics in patients with SHD (n = 132) versus without SHD (n = 516) and those with SND (n = 74) versus without SND (n = 574). ERPs were measured at the high and low right atrium, proximal, and distal coronary sinus.</AbstractText>(1) Patients with SHD had older age (P < 0.001), greater left atrial (LA) volume (P < 0.001), LA pressure (P = 0.002), and plasma proatrial natriuretic peptide (P = 0.005) than patients without SHD. (2) Patients with SND were older (P = 0.004), more likely female (P = 0.004), and had lower body weight (P < 0.001) and higher E/E' (P < 0.001) than those without SND. (3) The mean atrial ERP was significantly shorter in patients with PeAF than those with PAF (P < 0.001). The mean ERP was significantly longer in patients with AF with SHD/SND than those with lone AF (P = 0.006). (4) The clinical outcomes of RFCA were not significantly different between SHD/SND and lone AF for 14.8 ± 8.5 months of follow-up period.</AbstractText>The mean atrial ERP was shorter in patients with PeAF than those with PAF due to electrical remodeling. In contrast, AF patients with SHD/SND showed a more prolonged mean atrial ERP than those with lone AF, associated with LA enlargement or left ventricular diastolic dysfunction.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,626 | Potassium-induced conversion of ventricular fibrillation after aortic declamping. | The anti-fibrillatory effect of potassium is well recognized from experimental models. There have, however, been very few clinical reports on the use of potassium to convert ventricular fibrillation (VF) after cardioplegic arrest.</AbstractText>In total, 8465 adult patients undergoing cardiac operations on cardiopulmonary bypass (CPB) and with cold antegrade crystalloid cardioplegic arrest were consecutively enrolled in a database. Patients with VF after removal of the aortic clamp were given 20 mmol potassium, and if needed an extra 10 mmol, in the perfusion line and the conversion rate was registered. Preoperative and intraoperative factors possibly related to the occurrence of post-ischaemic VF were assessed.</AbstractText>Of these, 1721 (20%) patients had VF and 1366 of these (79%) were successfully treated with potassium infusion. Only 355 (21%) patients (4% of all operations) had direct-current countershock. The need for pacing was lower in the treatment group compared with the non-treatment group (P <0.001). Multivariate analysis revealed as the main findings that age, gender, amount of cardioplegia related to body mass index (BMI), and blood transfusion during the time of CPB had a highly significant (P <0.001) impact on reducing the rate of post-arrest VF. Somewhat contrary to expectation, left ventricular hypertrophy (LVH) was not a significant factor (P = 0.32) for post-arrest VF. No conversion by potassium was significant for age (P <0.001), gender (P <0.001) and LVH (P <0.001), but not for blood transfusion during CPB (P = 0.38) and for the ratio of cardioplegia-BMI (P = 0.26).</AbstractText>The results from this register study demonstrate that potassium infusion is an effective and convenient first-hand measure to convert post declamping VF on CPB.</AbstractText> |
13,627 | Mathematical modeling of atrial fibrillation. | Electrical activity of the heart during ventricular fibrillation was modeled as a sum of N independent pulse streams with various amplitude-frequency and phase characteristics. The data of computational experiments were compared with the results of actual physiological experiments on dogs. Identification of the model was performed using the least square method. The proposed technique provides the computer simulation for studies of the internal structure of irregularities of atrial fibrillation. |
13,628 | Comparison of four single-drug regimens on ventricular rate and arrhythmia-related symptoms in patients with permanent atrial fibrillation. | Rate control of atrial fibrillation (AF) is a main treatment modality. However, data are scarce on the relative efficacy of calcium channel blockers and β blockers or between drugs within each class. The purpose of the present study was to compare the effect of 4 rate-reducing, once-daily drug regimens on the ventricular heart rate and arrhythmia-related symptoms in patients with permanent AF. We included 60 patients (mean age 71 ± 9 years, 18 women) with permanent AF in an investigator-blind cross-over study. Diltiazem 360 mg/day, verapamil 240 mg/day, metoprolol 100 mg/day, and carvedilol 25 mg/day were administered for 3 weeks in a randomized sequence. The 24-hour heart rate was measured using Holter monitoring, and arrhythmia-related symptoms were assessed using the Symptom Checklist questionnaire before randomization and on the last day of each treatment period. The 24-hour mean heart rate was 96 ± 12 beats/min at baseline (no treatment), 75 ± 10 beats/min with diltiazem, 81 ± 11 beats/min with verapamil, 82 ± 11 beats/min with metoprolol, and 84 ± 11 beats/min with carvedilol. All drugs reduced the heart rate compared to baseline (p <0.001 for all). The 24-hour heart rate was significantly lower with diltiazem than with any other drug tested (p <0.001 for all). Compared to baseline, diltiazem significantly reduced both the frequency (p <0.001) and the severity (p = 0.005) of symptoms. In contrast, verapamil reduced symptom frequency only (p = 0.012). In conclusion, diltiazem 360 mg/day was the most effective drug regimen for reducing the heart rate in patients with permanent AF. Arrhythmia-related symptoms were reduced by treatment with the calcium channel blockers diltiazem and verapamil, but not by the β blockers. |
13,629 | Implantable cardioverter defibrillator shocks are prospective predictors of anxiety. | To examine the temporal contingency of anxiety and implantable cardioverter defibrillator (ICD) therapy (anti-tachycardia-pacing and shocks to prevent ventricular tachycardia and/or fibrillation).</AbstractText>It is under debate whether anxiety is a precursor and/or consequence of ICD-therapy.</AbstractText>In a prospective longitudinal study, fifty-four patients undergoing first-time ICD-implantation were assessed for anxiety, frequency of ICD-shocks and anti-tachycardia-pacing up to two days before ICD-implantation (T0) and twelve months later (T1).</AbstractText>Anxiety at T0 did not predict frequency of ICD-shocks at T1, but ICD-shocks significantly predicted increased anxiety at T1. In contrast, anxiety at T0 and T1 was unrelated to frequency of anti-tachycardia-pacing. Effects remained stable when we controlled for potentially confounding variables (e.g. age, sex, cardiac health and depression at T0).</AbstractText>Our findings indicate that repeated ICD-shocks are a cause of anxiety in ICD-patients rather than a consequence, thus shock frequency should be minimized.</AbstractText>Copyright © 2013 Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,630 | Mechanical discoordination increases continuously after the onset of left bundle branch block despite constant electrical dyssynchrony in a computational model of cardiac electromechanics and growth. | To test whether a functional growth law leads to asymmetric hypertrophy and associated changes in global and regional cardiac function when integrated with a computational model of left bundle branch block (LBBB).</AbstractText>In recent studies, we proposed that cardiac myocytes grow longer when a threshold of maximum fibre strain is exceeded and grow thicker when the smallest maximum principal strain in the cellular cross-sectional plane exceeds a threshold. A non-linear cardiovascular model of the beating canine ventricles was combined with the cellular growth law. After inducing LBBB, the ventricles were allowed to adapt in shape over time in response to mechanical stimuli. When subjected to electrical dyssynchrony, the combined model of ventricular electromechanics, haemodynamics, and growth led to asymmetric hypertrophy with a faster increase of wall mass in the left ventricular (LV) free wall (FW) than the septum, increased LV end-diastolic and end-systolic volumes, and decreased LV ejection fraction. Systolic LV pressure decreased during the acute phase of LBBB and increased at later stages. The relative changes of these parameters were similar to those obtained experimentally. Most of the dilation was due to radial and axial fibre growth, and hence altered shape of the LVFW.</AbstractText>Our previously proposed growth law reproduced measured dyssynchronously induced asymmetric hypertrophy and the associated functional changes, when combined with a computational model of the LBBB heart. The onset of LBBB leads to a step increase in LV mechanical discoordination that continues to increase as the heart remodels despite the constant electrical dyssynchrony.</AbstractText> |
13,631 | Management of ventricular and atrial arrhythmias in humans: towards a patient-specific approach. | The strategy of sudden cardiac death prevention by implantable cardioverter defibrillator, in primary prevention, is mainly based on the value of ejection fraction. That means that the approach is not really patient specific. A lot of implanted patients will not receive any shock. The implantation of large categories of patients is interesting on a global therapeutical point of view but, when considering the economical aspects, it would be more useful to have better selection criteria in order to obtain a more patient-specific approach, avoiding implanting patients who will never receive shocks. The parameters commonly used to select patients for implantations have a good negative predictive value but a low positive predictive value. Concerning atrial fibrillation the approach is quite different. Antiarrhythmic drug treatment has shown many limitations. Antiarrhythmic drugs are useful and safe in atrial fibrillation patients only if the contra-indications are strictly respected. The main difficulty concerns patients with both heart failure and atrial fibrillation. The story of Dronedarone development is illustrative of the necessity of a patient-specific approach in the treatment strategy of atrial fibrillation. The ATHENA trial made with Dronedarone showed a benefit in patients with underlying heart disease but no patient with advanced cardiopathy was included in the study. On the contrary, the PALLAS trial has clearly shown that the drug is contra-indicated in patients with any type of heart failure. In atrial fibrillation, a patient-specific approach is mandatory. This review illustrates the dichotomy of the two different approaches. |
13,632 | Low doses of intravenous epinephrine for refractory sustained monomorphic ventricular tachycardia. | We report three cases of sustained monomorphic ventricular tachycardia (VT) in the setting of coronary artery disease, resistant to beta-blockers in two patients and to amiodarone in all, successfully terminated by low doses of intravenous (IV) epinephrine. VT was the first manifestation of coronary artery disease in one patient, whereas the other two patients had a previous history of myocardial infarction and were recipients of an implantable cardioverter-defibrillator (ICD). One of these two patients experienced an arrhythmic storm. All had hemodynamic instability at the time of epinephrine administration. A single slow administration of IV epinephrine (0.5 to 1 mg administered over 30 to 60 s) restored sinus rhythm after 30-90 s with only minor side effects. In the ICD patient with recurrent VT and several cardioversions due to transformation of VT to ventricular fibrillation, epinephrine injection led to the avoidance of further shocks. Although potentially harmful, low doses of IV epinephrine used alone or in combination with beta-blocker treatment and electrical cardioversion may be an alternative effective therapy for sustained monomorphic VT refractory to amiodarone. The role of epinephrine in the termination of VT should be studied further, especially in patients pre-treated with amiodarone in combination with beta-blockers. |
13,633 | Effects of short-term administration of estradiol on reperfusion arrhythmias in rats of different ages. | Little is known about age-related differences in short-term effects of estradiol on ischemia-reperfusion (I/R) insults. The present study was designed to evaluate the effects of short-term treatment with estradiol on reperfusion arrhythmias in isolated hearts of 6-7-week-old and 12-14-month-old female rats. Wistar rats were sham-operated, ovariectomized and treated with vehicle or ovariectomized and treated with 17β-estradiol (E2; 5 µg·100 g-1·day-1) for 4 days. Hearts were perfused by the Langendorff technique. Reperfusion arrhythmias, i.e., ventricular tachycardia and/or ventricular fibrillation, were induced by 15 min of left coronary artery ligation and 30 min of reperfusion. The duration and incidence of I/R arrhythmias were significantly higher in young rats compared to middle-aged rats (arrhythmia severity index: 9.4 ± 1.0 vs 3.0 ± 0.3 arbitrary units, respectively, P < 0.05). In addition, middle-aged rats showed lower heart rate, systolic tension and coronary flow. Four-day E2 treatment caused an increase in uterine weight. Although E2 administration had no significant effect on the duration of I/R arrhythmias in middle-aged rats, it induced a marked reduction in the rhythm disturbances of young rats accompanied by a decrease in heart rate of isolated hearts. Also, this reduction was associated with an increase in QT interval. No significant changes were observed in the QT interval of middle-aged E2-treated rats. These data demonstrate that short-term estradiol treatment protects against I/R arrhythmias in hearts of young female rats. The anti-arrhythmogenic effect of estradiol might be related to a lengthening of the QT interval. |
13,634 | Role of late sodium channel current block in the management of atrial fibrillation. | The anti-arrhythmic efficacy of the late sodium channel current (late I(Na)) inhibition has been convincingly demonstrated in the ventricles, particularly under conditions of prolonged ventricular repolarization. The value of late I(Na) block in the setting of atrial fibrillation (AF) remains poorly investigated. All sodium channel blockers inhibit both peak and late I(Na) and are generally more potent in inhibiting late vs. early I(Na). Selective late I(Na) block does not prolong the effective refractory period (ERP), a feature common to practically all anti-AF agents. Although the late I(Na) blocker ranolazine has been shown to be effective in suppression of AF, it is noteworthy that at concentrations at which it blocks late I(Na) in the ventricles, it also potently blocks peak I(Na) in the atria, thus causing rate-dependent prolongation of ERP due to development of post-repolarization refractoriness. Late I(Na) inhibition in atria is thought to suppress intracellular calcium (Ca(i))-mediated triggered activity, secondary to a reduction in intracellular sodium (Na(i)). However, agents that block late I(Na) (ranolazine, amiodarone, vernakalant, etc) are also potent atrial-selective peak I(Na) blockers, so that the reduction of Na(i) loading in atrial cells by these agents can be in large part due to the block of peak I(Na). The impact of late I(Na) inhibition is reduced by the abbreviation of the action potential that occurs in AF patients secondary to electrical remodeling. It stands to reason that selective late I(Na) block may contribute more to inhibition of Ca(i)-mediated triggered activity responsible for initiation of AF in clinical pathologies associated with a prolonged atrial APD (such as long QT syndrome). Additional studies are clearly needed to test this hypothesis. |
13,635 | The neuroprotective effects of intraperitoneal injection of hydrogen in rabbits with cardiac arrest. | The purpose of this study was to investigate the neuroprotective effects of intraperitoneal injection of hydrogen (H2) in rabbits with cardiac arrest (CA).</AbstractText>A rabbit model of CA was established by the delivery of alternating current between the esophagus and chest wall to induce ventricular fibrillation. Before CA, the animals were randomly divided into four groups: a sham group (no CA), a CA group, a CA + low dose (10 ml/kg) H2 group (CA + H2 group 1), and a CA + high dose (20 ml/kg) H2 group (CA + H2 group 2). In the first experiment, animals were observed for 72 h after the restoration of spontaneous circulation (ROSC). The neurological scores were assessed at 24, 48 and 72 h after ROSC. The rabbits that survived until 72 h were sacrificed using an overdose of anesthetic, and the brain tissues were collected and Nissl-stained to observe nerve cell damage in the hippocampal CA1 area. In addition, TUNEL assay was performed to detect apoptosis. In the second experiment, animals were observed for 6h after ROSC. Blood samples and brain hippocampal tissues were collected, and differences in oxidative stress indicators were compared among the four groups.</AbstractText>Intraperitoneal injection of H2 improved the 72-h survival rate and neurological scores, reduced neuronal injury and inhibited neuronal apoptosis. Intraperitoneal injection of H2 reduced oxidative stress indicators in the plasma and hippocampal tissues and enhanced antioxidant enzyme activity. No significant difference was observed between the two CA groups treated with different doses of H2.</AbstractText>Intraperitoneal injection of H2 is a novel hydrogen administration method and can reduce cerebral ischemia-reperfusion injury and improve the prognosis of cardiopulmonary cerebral resuscitation in a rabbit model of CA.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,636 | Ventricular fibrillation resulting from diaphragmatic stimulation during gastric bypass surgery. | Gastric bypass operations are common and severely obese patients are prone to arrhythmias, particularly atrial fibrillation. Intraoperative ventricular arrhythmias during bariatric surgery have not been reported previously.</AbstractText>A 35-year-old, severely obese, diabetic woman with no other prior medical history underwent thorough preoperative cardiovascular evaluation before having laparoscopic Roux-en-Y gastric bypass. Intraoperatively she developed sudden onset ventricular fibrillation during the use of unipolar electrocautery near the Angle of His. The procedure was aborted, and the patient underwent repeat cardiovascular assessment including coronary angiography and serial electrophysiology studies before being unremarkably re-operated 6 months later, at which time a harmonic scalpel was used for dissection. 12 months post operation, the patient remains asymptomatic.</AbstractText>Owing to the proximity of the right ventricle overlying the diaphragm, far-field stimulation was likely responsible for inducing VF.</AbstractText>Copyright © 2012 S. Karger GmbH, Freiburg.</CopyrightInformation> |
13,637 | Inhibition of p38 MAPK during ischemia, but not reperfusion, effectively attenuates fatal arrhythmia in ischemia/reperfusion heart. | The mitogen-activated protein kinases (MAPKs) play an important role in ischemia/reperfusion (I/R) injury. Previous evidence suggests that p38 MAPK inhibition before ischemia is cardioprotective. However, whether p38 MAPK inhibition during ischemia or reperfusion provides cardioprotection is not well known. We tested the hypothesis that p38 MAPK inhibition at different times during I/R protects the heart from arrhythmias, reduces the infarct size, and attenuates ventricular dysfunction. Adult Wistar rats were subject to a 30-minute left anterior descending coronary artery occlusion, followed by a 120-minute reperfusion. A p38 MAPK inhibitor, SB203580, was given intravenously before left anterior descending coronary artery occlusion, during ischemia, or at the onset of reperfusion. The results showed that SB203580 given either before or during ischemia, but not at the onset of reperfusion, decreased the ventricular tachycardia/ventricular fibrillation (VT/VF) incidence and heat shock protein 27 phosphorylation, and increased connexin 43 phosphorylation. The infarct size and cytochrome c level was decreased in all SB203580-treated rats, without the alteration of the total Bax/Bcl-2 expression. The ventricular function was improved only in SB203580-pretreated rats. These findings suggest that timing of p38 MAPK inhibition with respect to onset of ischemia is an important determinant of therapeutic efficacy. |
13,638 | Increasing survival rate from commotio cordis. | Commotio cordis events due to precordial blows triggering ventricular fibrillation are a cause of sudden death (SD) during sports and also daily activities. Despite the absence of structural cardiac abnormalities, these events have been considered predominantly fatal with low survival rates.</AbstractText>To determine whether expected mortality rates for commotio cordis have changed over time, associated with greater public visibility.</AbstractText>US Commotio Cordis Registry was accessed to tabulate frequency of reported SD or resuscitated cardiac arrest over 4 decades.</AbstractText>At their commotio cordis event, 216 study patients were 0.2-51 years old (mean age 15±9 years); 95% were males. Death occurred in 156 individuals (72%), while the other 60 (28%) survived. Proportion of survivors increased steadily with concomitant decrease in fatal events. For the initial years (1970-1993), 6 of 59 cases survived (10%), while during 1994-2012, 54 of 157 (34%) survived (P = .001). The most recent 6 years, survival from commotio cordis was 31 of 53 (58%), with survivor and nonsurvivor curves ultimately crossing. Higher survival rates were associated with more prompt resuscitation (40%<3 minutes vs 5%>3 minutes; P<.001) and participation in competitive sports (39%; P<.001), but with lower rates in African Americans (1 of 24; 4%) than in whites (54 of 166; 33%; P = .004). Independent predictors of mortality were black race (P = .045) and participation in noncompetitive sports (P = .002), with an on-site automated external defibrillator use protective against SD (P = .01).</AbstractText>Survival from commotio cordis has increased, likely owing to more rapid response times and access to defibrillation, as well as greater public awareness of this condition.</AbstractText>Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,639 | Tpeak - Tend and Tpeak - Tend /QT ratio as markers of ventricular arrhythmia risk in cardiac resynchronization therapy patients. | Cardiac resynchronization therapy (CRT) increases transmural dispersion of repolarization (TDR) and can be pro-arrhythmic. However, overall arrhythmia risk was not increased in large-scale CRT clinical trials. Increased TDR as measured by T(peak ) -T(end) (TpTe) was associated with arrhythmia risk in CRT in a single-center study. This study investigates whether QT interval, TpTe, and TpTe/QT ratio are associated with ventricular arrhythmias in patients with CRT-defibrillator (CRT-D).</AbstractText>Post-CRT-D implant electrocardiograms of 128 patients (age 71.3 years ± 10.3) with at least 2 months of follow-up at our institution's device clinic (mean follow-up of 28.5 months ± 17) were analyzed for QT interval, TpTe, and TpTe/QT ratio. Incidence of ventricular arrhythmias was determined based on routine and directed device interrogations.</AbstractText>Appropriate implantable cardioverter-defibrillator therapy for sustained ventricular tachycardia or ventricular fibrillation was delivered in 18 patients (14%), and nonsustained ventricular tachycardia (NSVT) was detected but did not require therapy in 58 patients (45%). Patients who received appropriate defibrillator therapy had increased TpTe/QT ratio (0.24 ± 0.03 ms vs 0.20 ± 0.04, P = 0.0002) and increased TpTe (105.56 ± 20.36 vs 87.82 ± 22.32 ms, P = 0.002), and patients with NSVT had increased TpTe/QT ratio (0.22 ± 0.04 vs 0.20 ± 0.04, P = 0.016). Increased QT interval was not associated with risk of ventricular arrhythmia. The relative risk for appropriate defibrillator therapy of T(p) T(e) /QT ratio ≥ 0.25 was 3.24 (P = 0.016).</AbstractText>Increased TpTe and increased TpTe/QT ratio are associated with increased incidence of ventricular arrhythmias in CRT-D. The utility of TpTe interval and TpTe/QT ratio as potentially modifiable risk factors for ventricular arrhythmias in CRT requires further study.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,640 | Emergency department factors associated with survival after sudden cardiac arrest. | Sudden cardiac arrest (SCA) is a leading cause of death in the US. Recent innovations in post-arrest care have been demonstrated to increase survival. However, little is known about the impact of emergency department (ED) and hospital characteristics on survival to hospital admission and ultimate outcome.</AbstractText>We sought to describe the incidence of SCA presenting to the ED and to identify ED and hospital characteristics associated with survival to hospital admission.</AbstractText>We identified patients with diagnoses of atraumatic cardiac arrest or ventricular fibrillation (ICD-9 427.5 or 427.41) in the 2007 Nationwide Emergency Department Sample (NEDS), a nationally representative estimate of all ED admissions in the United States. We defined SCA as cardiac arrest in the out-of-hospital or ED settings. We used the NEDS sample design to generate nationally representative estimates of the incidence of SCA that presents to EDs. We performed unadjusted and adjusted analyses to examine the relation between patient, ED, and hospital characteristics and outcome using logistic regression. Our primary outcome was survival to hospital admission. Survival to hospital discharge was a secondary outcome. Data are presented as odds ratios (OR) with 95% confidence intervals (CI).</AbstractText>Of the 966 hospitals in the NEDS, 933 (96.6%) reported at least one SCA and were included in the analysis. We identified 38,593 cases of cardiac arrest representing an estimated 174,982 cases nationally. Overall ED SCA survival to hospital admission was 26.2% and survival to discharge was 15.7%. Greater survival to admission was seen in teaching hospitals (OR 1.3 95% CI 1.1-1.5, p=0.001), hospitals with ≥20,000 annual ED visits (OR 1.3 95% CI 1.1-1.6, p=0.003), and hospitals with percutaneous coronary intervention capability (OR 1.6 95% CI 1.4-1.8, p<0.001). Higher SCA volume (>40 annually) was associated with lower survival overall (OR 0.7 95% 0.6-0.9, p=0.010), but not when transferred patients were excluded from the analysis (OR 0.8 95% CI 0.6-1.1, p=0.116).</AbstractText>An estimated 175,000 cases of SCA present to or occur in US EDs each year. Percutaneous coronary intervention capability, ED volume, and teaching status were associated with higher survival to hospital admission. Emergency departments with higher annual SCA volume had lower survival rates, possibly because they transfer fewer patients. An improved understanding of the contribution of ED care to survival following SCA may be useful in advancing our understanding of how best to organize a system of care to ensure optimal outcomes for patients with SCA.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,641 | Initial bispectral index may identify patients who will awaken during therapeutic hypothermia after cardiac arrest: a retrospective pilot study. | Patients sustain a range of neurologic injuries after cardiac arrest, and determining which patients should be treated with therapeutic hypothermia (TH) is complex, often confounded by sedation and neuromuscular blockade (NMB). We evaluated bispectral index (BIS) monitoring as a tool to identify adult patients that awakened during therapeutic hypothermia.</AbstractText>Review of prospectively collected registry data, with retrospective chart review of patient descriptions during hypothermia. Data are presented as median (interquartile range).</AbstractText>7 of 309 patients (2.2%) treated with TH over 6 years awoke (followed commands) prior to completing hypothermia. Median age was 58 (54-66) years; 71% were male, cardiac arrest was witnessed in 6 (86%) and out-of-hospital in 6 (86%), and 4 patients (57%) were transferred from another hospital. 5 patients (71%) had an initial rhythm of ventricular tachycardia or fibrillation, time to return of spontaneous circulation was 17 (12-23)min. The BIS value after first NMB dose during TH was 63, 45, 43, 52, 62, 54, and 42 (median 52, IQR 44-58, 95% confidence interval 46-58). The median BIS value in the remaining data set (n=302) was 18 (6-36), p<0.001, and only 6% of BIS1 values were >46.</AbstractText>Patients who awakened early had higher BIS values after the first dose of NMB. Processed EEG values after cardiac arrest may provide additional information that could assist with determining best treatment.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,642 | Results of clinical application of the modified maze procedure as concomitant surgery. | Atrial fibrillation is the most common cardiac arrhythmia and is associated with significant morbidity and mortality. The classic cut-and-sew maze procedure is successful in 85-95% of patients. However, the technical complexity has prompted modifications of the maze procedure. The objective of this study was to retrospectively evaluate the clinical safety and efficacy of the maze treatment performed at our institution.</AbstractText>From March 2001 until February 2009, 169 patients underwent a modified maze procedure for atrial fibrillation at the Erasmus MC, Rotterdam. Patient characteristics, surgical procedure and follow-up data were obtained by reviewing the medical charts and consulting with the referring physicians. The efficacy of the procedure as measured by AF recurrence was analysed with a repeated measurements model. The quality of life of the patients was assessed with the SF-36 (a short-form health survey with 36 questions) questionnaire and compared with that of the general Dutch population.</AbstractText>Of the 169 patients who underwent a modified maze procedure, 163 had their maze procedure as a concomitant procedure. The 30-day mortality rate was 4.7% (n = 8). The rate of post-procedural AF recurrence varied significantly over time (P < 0.0001). Decreased left ventricular function, increased age and higher preoperative creatinine levels were predictors of AF recurrence. Quality of life, as measured with the SF-36 questionnaire, was comparable with that of the Dutch population for all health domains.</AbstractText>Concomitant maze is a relatively safe treatment that eliminates atrial fibrillation in the majority of patients, although the probability of recurrent AF increases with the passage of time. Decreased left ventricular function, increased age and higher preoperative creatinine levels are associated with an increased risk of AF recurrence.</AbstractText> |
13,643 | Usefulness of inducible ventricular tachycardia to predict long-term adverse outcomes in arrhythmogenic right ventricular cardiomyopathy. | The role of the electrophysiologic (EP) study for risk stratification in patients with arrhythmogenic right ventricular cardiomyopathy is controversial. We investigated the role of inducible sustained monomorphic ventricular tachycardia (SMVT) for the prediction of an adverse outcome (AO), defined as the occurrence of cardiac death, heart transplantation, sudden cardiac death, ventricular fibrillation, ventricular tachycardia with hemodynamic compromise or syncope. Of 62 patients who fulfilled the 2010 Arrhythmogenic Right Ventricular Cardiomyopathy Task Force criteria and underwent an EP study, 30 (48%) experienced an adverse outcome during a median follow-up of 9.8 years. SMVT was inducible in 34 patients (55%), 22 (65%) of whom had an adverse outcome. In contrast, in 28 patients without inducible SMVT, 8 (29%) had an adverse outcome. Kaplan-Meier analysis showed an event-free survival benefit for patients without inducible SMVT (log-rank p = 0.008) with a cumulative survival free of an adverse outcome of 72% (95% confidence interval [CI] 56% to 92%) in the group without inducible SMVT compared to 26% (95% CI 14% to 50%) in the other group after 10 years. The inducibility of SMVT during the EP study (hazard ratio [HR] 2.99, 95% CI 1.23 to 7.27), nonadherence (HR 2.74, 95% CI 1.3 to 5.77), and heart failure New York Heart Association functional class II and III (HR 2.25, 95% CI 1.04 to 4.87) were associated with an adverse outcome on univariate Cox regression analysis. The inducibility of SMVT (HR 2.52, 95% CI 1.03 to 6.16, p = 0.043) and nonadherence (HR 2.34, 95% CI 1.1 to 4.99, p = 0.028) remained as significant predictors on multivariate analysis. This long-term observational data suggest that SMVT inducibility during EP study might predict an adverse outcome in patients with arrhythmogenic right ventricular cardiomyopathy, advocating a role for EP study in risk stratification. |
13,644 | Outpatient cardiac telemetry detects a high rate of atrial fibrillation in cryptogenic stroke. | The etiology of cerebral ischemia is undetermined in one-third of patients upon discharge. Occult paroxysmal atrial fibrillation (PAF) is considered a potential etiology. A high rate of PAF detection with 21-day mobile cardiac outpatient telemetry (MCOT) has been reported in two small studies. Optimal monitoring duration and factors predicting PAF have not been adequately defined.</AbstractText>We performed a retrospective analysis on patients evaluated by MCOT monitoring within 6 months of a cryptogenic stroke or TIA. Multivariate analysis with survival regression methods was performed using baseline characteristics to determine predictive risk factors for detection of PAF. Kaplan-Meier estimates were computed for 21-day PAF rates.</AbstractText>We analyzed 156 records; PAF occurred in 27 of 156 (17.3%) patients during MCOT monitoring of up to 30 days. The rate of PAF detection significantly increased from 3.9% in the initial 48 h, to 9.2% at 7 days, 15.1% at 14 days, and 19.5% by 21 days (p<0.05). Female gender, premature atrial complex on ECG, increased left atrial diameter, reduced left ventricular ejection fraction and greater stroke severity were independent predictors of PAF detection on multivariate analysis with strongest correlation seen for premature atrial complex on ECG (HR 13.7, p=0.001).</AbstractText>MCOT frequently detects PAF in patients with cryptogenic stroke and TIA. Length of monitoring is strongly associated with detection of PAF, with an optimal monitoring period of at least 21 days. Of the predictors of PAF detection, the presence of premature atrial complexes on ECG held the strongest correlation with PAF.</AbstractText>Published by Elsevier B.V.</CopyrightInformation> |
13,645 | Twelve-lead electrocardiography in the young: physiologic and pathologic abnormalities. | BACKGROUND/ OBJECTIVE: The purpose of the present study was to analyze the prevalence of physiologic and pathologic ECG abnormalities in a cohort of young conscripts that represents the whole young generation of today.</AbstractText>ECGs of all Swiss citizens who underwent conscription for the army during a 29-month period were analyzed manually.</AbstractText>ECGs of 43,401 conscripts (mean age 19.2 ± 1.1 years) were analyzed; 158 conscripts were female. Incomplete right bundle branch block was found in 5870 (13.5%) and left anterior fascicular block in 360 (0.83%). First-degree AV block was present in 329 (0.8%) and Mobitz type I (Wenckebach) second-degree AV block in 3 (0.01%). Early repolarization was observed in 1035 (2.4%), T-wave inversion in 39 (0.09%), and minor T-wave changes in 182 (0.42%). Brugada-like abnormalities were observed in 6 (0.01%). None of the conscripts had atrial fibrillation or flutter.</AbstractText>ECG abnormalities can be found in a relatively large proportion of young individuals. Incomplete right bundle branch block, left fascicular block, and first-degree AV block are the most frequent findings. No conscript presented with atrial fibrillation or flutter.</AbstractText>Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,646 | Ventricular arrhythmias and sudden cardiac death. | Management strategies for ventricular arrhythmias are guided by the risk of sudden death and severity of symptoms. Patients with a substantial risk of sudden death usually need an implantable cardioverter defibrillator (ICD). Although ICDs effectively end most episodes of ventricular tachycardia or ventricular fibrillation and decrease mortality in specific populations of patients, they have inherent risks and limitations. Generally, antiarrhythmic drugs do not provide sufficient protection from sudden death, but do have a role in reducing arrhythmias that cause symptoms. Catheter ablation is likewise important for reducing the frequency of spontaneous arrhythmias and is curative for some patients, usually those with idiopathic arrhythmias and no heart disease. Arrhythmia surgery is now infrequent, offered by only a few specialised centres for refractory arrhythmias. Advances in understanding of genetic arrhythmia syndromes and in technology for mapping and ablation of ventricular arrhythmias, and enhanced algorithms in implantable devices for rhythm management, have contributed to improved outcomes. |
13,647 | Ventricular arrhythmias: device therapy and ablation. | There are few randomized, well-controlled studies to guide decision making with respect to the treatment of ventricular arrhythmias in the elderly treated with either device implantation or catheter ablation. Although some data are conflicting, the elderly appear to have a greater degree of risk related to treatment compared with younger ones; however, this increased risk is in part a consequence of age itself and comorbid conditions. Conversely, in terms of benefit, although the data may again be mixed, there is ample information indicating that age should not contraindicate aggressive treatment when accepted indications for intervention exist. |
13,648 | Mechanisms of arrhythmias and conduction disorders in older adults. | Aging is associated with an increased prevalence of cardiac arrhythmias, which contribute to higher morbidity and mortality in the elderly. The frequency of cardiac arrhythmias, particularly atrial fibrillation and ventricular tachyarrhythmia, is projected to increase as the population ages, greatly impacting health care resource utilization. Several clinical factors associated with the risk of arrhythmias have been identified in the population, yet the molecular bases for the increased predisposition to arrhythmogenesis in the elderly are not fully understood. This review highlights the epidemiology of cardiac dysrhythmias, changes in cardiac structure and function associated with aging, and the basis for arrhythmogenesis in the elderly. |
13,649 | Further insights into the underlying electrophysiological mechanisms for reduction of atrial fibrillation by ranolazine in an experimental model of chronic heart failure. | Ranolazine (RAN) was reported to be effective and safe in converting atrial fibrillation (AF) to sinus rhythm by administration of a single dose ('pill in the pocket') to patients with structural heart disease. This study examines the underlying mechanisms for the antiarrhythmic benefit of RAN application in chronic heart failure (CHF).</AbstractText>In 10 female rabbits, CHF was induced by rapid ventricular pacing, leading to a significant decrease in ejection fraction in the presence of a dilated left ventricle and atrial enlargement. Twelve rabbits were sham-operated and served as controls. Isolated hearts were perfused using the Langendorff method. Burst pacing was used to induce AF. Monophasic action potential recordings showed an increase of atrial action potential duration (aAPD) and effective refractory period (aERP) in CHF hearts compared with sham hearts. Infusion of acetylcholine (1 µM) and isoproterenol (1 µM) led to AF in all failing hearts and in 11 sham hearts. Simultaneous infusion of RAN (10 µM) remarkably reduced inducibility of AF in 50% of sham and 50% of failing hearts. RAN had no effect on aAPD but significantly increased aERP, leading to a marked increase in atrial post-repolarization refractoriness. Moreover, RAN application moderately increased interatrial conduction time.</AbstractText>RAN has been shown to be effective in reducing the inducibility of AF in an experimental model of AF. The antiarrhythmic effect is mainly due to development of atrial post-repolarization refractoriness and a moderate increase in conduction time. The described electrophysiological mechanisms remain preserved in the setting of CHF.</AbstractText> |
13,650 | [Anticoagulant therapy in connection with cardioversion in patients with atrial fibrillation]. | We present data on possibility of anticoagulant therapy in conjunction with electrical cardioversion in patients with atrial fibrillation using novel anticoagulant - dabigatran - and a case of successful lysis of thrombus in the left ventricular cavity at the background of its administration. |
13,651 | Right atrial preference pacing algorithm in the prevention of paroxysmal atrial fibrillation in myotonic dystrophy type 1 patients: a long term follow-up study. | Atrial Preference Pacing (APP) is a pacemaker (PM) algorithm that works by increasing the atrial pacing rate to achieve continuous suppression of a spontaneous atrial rhythm and prevent supraventricular tachyarrhythmias. We have previously shown that atrial preference pacing may significantly reduce the number and the duration of AF episodes in myotonic dystrophy type 1 (DM1) patients who are paced for standard indications.However, the role that APP therapies play in the prevention of AF in a long-term period remains still unclear. Aim of the present prospective study was to evaluate whether this beneficial effect is maintained for 24-months follow-up period.To this aim, 50 patients with Myotonic Dystrophy type 1 who underwent dual-chamber PM implantation for first- and second- degree atrioventricular block, were consecutively enrolled and followed for 2 years. One month later the stabilization period, after the implantation, they were randomized to APP algorithm programmed OFF or ON for 6 months each, using a cross-over design, and remained in the same program for the second year. The results showed that while the number of AF episodes during active treatment (APP ON phases) was lower than that registered during no treatment (APP OFF phases), no statistically significant difference was found in AF episodes duration between the two phases. Furthermore, during the APP OFF and APP ON phases, the percentage of atrial pacing was 0 and 99%, respectively, while the percentage of ventricular pacing did not show differences statistically significant (11 vs. 9%, P = 0.2). Atrial premature beats were significantly higher during APP OFF phases than during APP ON phases. Lead parameters remained stable over time and there were no lead-related complications. Based on these 24-months follow-up data, we can conclude that, in DM1 patients who underwent dual-chamber PM implantation, APP is an efficacy algorithm for preventing paroxysmal AF even in long term periods. |
13,652 | High signal intensity on T2-weighted cardiac magnetic resonance imaging correlates with the ventricular tachyarrhythmia in hypertrophic cardiomyopathy. | Late gadolinium enhancement (LGE) with cardiac magnetic resonance (CMR) can predict ventricular arrhythmia and poor prognosis in hypertrophic cardiomyopathy (HCM) patients. Although myocardial T2-high signal has been reported to appear within LGE in those patients, its clinical significance remains unclear. We investigated the relationship between the T2-high signal and nonsustained ventricular tachycardia (NSVT) in HCM patients. Eighty-one HCM patients who underwent Holter ECG and CMR including T2-weighted and LGE imaging were retrospectively recruited. They were divided into NSVT-positive and NSVT-negative groups. We compared the clinical and CMR characteristics between both of the groups, and assessed predictors of NSVT with multivariate analysis. Myocardial T2-high signal was observed in 15/81 (18.5 %) patients. Each T2-high signal was localized within LGE. Significantly in the NSVT-positive group, the prevalence of atrial fibrillation [5/17 (29.4 %) vs. 2/64 (3.1 %), p = 0.0006] and T2-high signal [9/17 (52.9 %) vs. 6/64 (9.4 %), p < 0.0001] and the left ventricular (LV) end-systolic volume index (32.2 ± 15.9 ml/m(2) vs. 23.3 ± 14.9 ml/m(2), p = 0.034) and the number of segments with LGE (5.8 ± 3.3 vs. 2.7 ± 2.7, p < 0.0001) was increased, and the LV ejection fraction (54.8 ± 10.9 % vs. 65.1 ± 10.6 %, p = 0.0007) was decreased, compared to the NSVT-negative group. On multivariate analysis, the presence of atrial fibrillation (OR 29.49, p = 0.0025) and DM (OR 7.36, p = 0.0455) and T2-high signal (OR 14.96, p = 0.0014) and reduced LV ejection fraction (OR 0.93, p = 0.0222) were significantly associated with NSVT. The presence of myocardial T2-high signal is a significant independent predictor of NSVT in HCM patients. |
13,653 | [Clinical characteristics, management and prognostic evolution of patients admitted within six hours of symptom onset with st-segment elevation acute myocardial infarction complicated by cardiogenic shock : twenty year monocentric study]. | Cardiogenic shock is one of the most serious complications of the acute myocardial infarction. Advances in interventional cardiology and early reperfusion strategy improved its management.</AbstractText>Analysis of the clinical characteristics, management and prognostic evolution of patients admitted within 6 hours onset with ST-segment elevation acute myocardial infarction complicated by cardiogenic shock.</AbstractText>Follow-up study based on 2200 consecutive patients admitted with STEMI within 6 hours of symptom onset from 1988 to 2008. Among them 114 matched the criteria of cardiogenic shock. These were divided in two groups, according to the period: group 1 (N=57, among the first 1100 STEMI from 1988 to 1998) and group 2 (N=57, among the following 1100 STEMI from 1999 to 2008).</AbstractText>This trial shows a similar rate of cardiogenic shock in STEMI (5%) in both 1100 patients groups. There is no overall change in patient's clinical characteristics, but improvements in earlier management, prehospital fibrinolysis and ventricular fibrillation treatment have been detected. Primary percutaneous coronary intervention was the most common revascularisation strategy. The proportion of patients achieving acute TIMI-3 flow in the infarct related artery increased (61% vs 80%, p= 0.11) but the mortality was still high (74% vs 63%, p= 0.22).</AbstractText>The clinical characteristics of cardiogenic shock remain unchanged; its management is more successful with more often early reperfusion. The decline of mortality is unfortunately not significant. More aggressive treatment should probably be considered to improve outcomes.</AbstractText> |
13,654 | [Public access defibrillation in the Sorrento Peninsula]. | Early cardiac defibrillation is the only effective therapy to stop ventricular fibrillation or pulseless ventricular tachycardia. It is still considered the gold standard for the treatment of ventricular tachycardia/fibrillation, and is the only intervention capable of improving survival in cardiac arrest survivors. Timing of intervention, however, is crucial because after only 10 min success rates are very low (0-2%). Unfortunately, adequate relief cannot always be provided within the necessary time. The purpose of the public access defibrillation project in Sorrento was to create fixed and mobile first aid with automated external defibrillators in combination with the local 118 emergency system. With the involvement of pharmacies, bathing establishments and schools, 31 equally distant sites for public access defibrillation were made available. This organization was supplemented by mobile units on the cars of the Municipal Police and Civil Protection, and on patrol boats in the harbor. |
13,655 | [Subcutaneous implantable cardioverter-defibrillators]. | Transvenous implantable cardioverter-defibrillators (ICD) for the primary and secondary prevention of sudden cardiac death due to ventricular tachycardia/fibrillation have led to a significant improvement in survival in high-risk populations. Although conventional transvenous ICD therapy is currently widely used, it is associated with severe intra- and perioperative complications related to the use of transvenous leads, mostly occurring late after implantation. The recent introduction of a new ICD system with fully subcutaneous sensing and shocking capabilities has provided a valuable therapeutic option for special patient groups, allowing to identify and stop malignant ventricular arrhythmias while discriminating them from high-rate supraventricular tachyarrhythmias. This has also given us the opportunity to analyze the advantages and limitations of both implantable lifesaving electrical therapies. In the present paper, the technical characteristics of subcutaneous ICDs are described along with the recent advances in clinical and experimental research that have led to the introduction of these devices into clinical practice (over 1000 patients have been treated worldwide since 2009). Subcutaneous ICDs are indicated for both primary and secondary prevention of cardiac arrest in patients at risk for acquired or congenital arrhythmogenic diseases, including those with an underlying genetic molecular mechanism, provided that they do not require antibradycardia or antitachycardia pacing or cardiac resynchronization therapy, which represent the main limitations of these new devices. A subcutaneous ICD system has the advantage of avoiding the need for transvenous leads, making its implantation or removal much simpler without requiring fluoroscopic guidance. In addition, subcutaneous ICDs can be used in children, young subjects and athletes, and in all patients for whom venous access may be difficult to achieve. |
13,656 | Subclinical cardiomyopathy and long QT syndrome: an echocardiographic observation. | Long QT syndrome (LQTS) is a cardiac channelopathy predisposing to syncope and sudden death secondary to LQT-triggered ventricular arrhythmias. Long QT syndrome has been regarded as a purely electrical disease. Recent reports have shown by echocardiography that LQTS patients have contraction abnormalities that are associated with cardiac arrhythmias. The purpose of this study was to determine the spectrum and prevalence of echocardiographic anomalies in a large cohort of patients diagnosed genetically and/or clinically with LQTS.</AbstractText>Two-dimensional and Doppler echocardiographic studies performed during medical evaluation in Mayo's LQTS Clinic were reviewed for 216 LQTS patients. Echocardiograms were evaluated for morphologic abnormalities and atrial and ventricular size and function. Left atrial volume was indexed by body mass. Arrhythmic events were defined as a history of aborted cardiac arrest, documented ventricular tachycardia or fibrillation, and syncope.</AbstractText>While 75% of patients had normal standard echocardiograms, 54 patients (25%) had at least one abnormal echocardiographic finding. Most common were subclinical cardiomyopathic changes, including increased left atrial volume index (n = 25), left or right ventricular enlargement (n = 7), and grade I-II diastolic dysfunction (n = 7). Left atrial volume index was higher in LQTS patients with arrhythmic events compared with those without (24.4 ± 5.5 mL/m(2) vs. 22.3 ± 6.1 mL/m(2) , P =.02). Corrected QT intervals and left atrial volume index correlated significantly albeit weakly (r(2) = 0.04, P <.01). Concomitant congenital heart disease was found in two patients.</AbstractText>Subclinical cardiomyopathic changes were found in nearly 20% of LQTS patients. Left atrial enlargement was the most common finding and was associated with prolonged corrected QT and arrhythmic events. These changes may stem from underlying contraction abnormalities caused by ion channel dysfunction.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,657 | Atrial fibrillation-associated remodeling does not promote atrial thrombus formation in canine models. | The most important complication of atrial fibrillation (AF) is thromboembolic stroke. Although AF-related remodeling is considered important in atrial thrombogenesis, its role never has been directly tested. This study assessed effects of AF-related remodeling on the atrial thrombogenic milieu by using radiofrequency ablation (RFA) to create a quantifiable prothrombotic nidus.</AbstractText>We studied normal control dogs (control, n=16) and 3 canine AF-models: (1) atrial tachycardia remodeling (ATR; n=16) induced by atrial tachypacing (400 bpm for 1 week, with atrioventricular block and ventricular pacing at 80 bpm); (2) congestive heart failure (CHF; n=14) attributable to ventricular tachypacing (240 bpm for 2 weeks); and (3) chronic AF (CAF; n=8) induced by atrial tachypacing (35±3 days) without atrioventricular block. CAF dogs had AF for 13±1 days until euthanization. After remodeling was established, RFA lesions were created in both atria. Half the ATR and CHF dogs were subjected to atrial tachypacing during 7-day post-RFA follow-up. Electrophysiological and echocardiographic studies were performed before RFA and 7 days after RFA, and then hearts were removed and atrial thrombi were quantified by histomorphometry. Burst-pacing-induced AF duration was significantly greater in ATR, CHF, and CAF groups versus control group. The atrial effective refractory period shortened in ATR and CAF groups. Left atrial diameter was significantly larger with CHF, but not with ATR. Neither total thrombus volume nor thrombus volume per lesion differed significantly among groups. Table.Properties of Ablation Lesions and Atrial Thrombi Experimental GroupControl (n=16)ATR (n=16)CHF (n=14)CAF (n=8)N of ablation lesions per dog6.9±0.36.6±0.27.2±0.26.9±0.4Ablation lesion area, mm(2)53.1±3.558.3±4.857.7±4.944.3±3.7Ablation lesion depth, mm5.2±0.25.1±0.35.3±0.25.2±0.2Ablation lesion volume, mm(3)205.2±17.8211.6±17.6231.5±29.0176.8±22.2N of thrombi per dog5.4±0.44.7±0.35.6±0.46.5±0.4Presence of thrombus, %80±572±577±695±3Mean thrombus volume in both atria, mm(3)20.8±3.414.9±2.212.2±2.622.5±5.6Mean thrombus volume in left atria, mm(3)8.2±1.54.0±0.95.5±1.68.1±3.3Mean thrombus volume in right atria, mm(3)30.1±5.422.7±4.317.9±4.132.8±8.3Total thrombus volume in both atria, mm(3)140.5±21.399.7±16.886.1±17.5131.1±22.7Total thrombus volume in left atria, mm(3)22.8±5.311.8±3.317.0±3.723.3±6.4Total thrombus volume in right atria, mm(3)117.7±21.587.8±17.269.1±16.1107.8±23.3Thrombus volume normalized to ablation lesion area in both atria, mm(3)/mm(2)0.5±0.10.4±0.11.5±1.10.8±0.3Thrombus volume normalized to ablation lesion volume in both atria0.2±0.10.1±0.00.5±0.40.3±0.1 ATR indicates atrial tachycardia remodeling; CAF, chronic atrial fibrillation; and CHF, congestive heart failure. There were no statistically significant differences for any groups vs control group for any of these variables studied.</AbstractText>None of the AF substrates tested, including sustained atrial tachycardia/AF itself, enhanced post-RFA atrial thrombus formation. Indices of electrical and structural remodeling did not predict post-RFA thrombogenic potential. Contrary to widely held but previously untested notions, we were unable to demonstrate prothrombotic effects of AF-related remodeling.</AbstractText> |
13,658 | Does chronic atrial fibrillation induce cardiac remodeling? | The aim of this study was to compare cardiac structure and function in patients with chronic atrial fibrillation (CAF), as opposed to patients with paroxysmal atrial fibrillation (PAF), and normal control subjects.</AbstractText>This study included 83 patients, divided into 3 groups: group A, 32 patients with CAF for ≥6 months; group B, 29 patients in sinus rhythm with a documented history of PAF; and group C, 22 patients without history of atrial fibrillation. Patients with CAF were older (71 years vs. 64 in group B, and 64 in group C). Apart from age, groups were clinically similar. After careful clinical evaluation, comprehensive echocardiography studies were performed including cardiac chambers' size, systolic and diastolic left ventricular function. Left atrium (LA) volume index was significantly larger in CAF than PAF and control patients: 39 ± 13 versus 34 ± 9 versus 25 ± 8 (P < 0.003). Left ventricular ejection fraction was lower in CAF: 53.8 ± 7 versus 61.6 ± 6.7 versus 58.4 ± 5.2% (P < 0.001). Isovolumic relaxation time was shorter in CAF, 65 ± 16 versus 82 ± 21 versus 81 ± 13 msec (P < 0.001). E/Vp was significantly greater in CAF 2.6 ± 0.8 versus 1.7 ± 0.4 versus 1.7 ± 0.5 (P < 0.001). Additional diastolic parameters were also significantly different.</AbstractText>These findings demonstrate that in patients with CAF structural and functional cardiac changes occur. Patients with CAF as opposed to both normal subjects and patients with PAF have larger left atria and reduced systolic and diastolic left ventricular function.</AbstractText>© 2012, Wiley Periodicals, Inc.</CopyrightInformation> |
13,659 | Complete absence of precordial R waves due to absence of left-sided pericardium. | Poor R-wave progression (PRWP) in the precordial leads on random ECG is relatively frequent in the general population and includes a broad differential diagnosis. Here, we present for the first time a case of complete absence of precordial R waves associated with a prominent R wave in aVR due to the absence of the left-sided pericardium in a 44-year-old woman who experienced sudden cardiac death. |
13,660 | A family with recurrent sudden death and no clinical clue. | Sudden cardiac death of a child is a devastating event for the family and an enormous challenge for the attending physician.</AbstractText>We report a family with repeat events of sudden cardiac death and recurrent ventricular fibrillation in a teenage girl, where autopsy data and clinical investigations were inconclusive. The diagnosis of catecholaminergic polymorphic ventricular tachycardia (CPVT) was established only following finding a gene mutation in the cardiac ryanodine receptor.</AbstractText>Interpretation of autopsy data, provocation testing and genetic testing in victims of sudden death and family members are discussed to correctly identify the cause and properly manage asymptomatic carriers in such families.</AbstractText>©2012, Wiley Periodicals, Inc.</CopyrightInformation> |
13,661 | Ventricular response during lungeing exercise in horses with lone atrial fibrillation. | Atrial fibrillation (AF) is the most important dysrhythmia affecting performance in horses and has been associated with incoordination, collapse and sudden death. Limited information is available on ventricular response during exercise in horses with lone AF.</AbstractText>To investigate ventricular response in horses with lone AF during a standardised lungeing exercise test.</AbstractText>A modified base-apex electrocardiogram was recorded at rest and during a standardised lungeing exercise test from 43 horses diagnosed with lone AF. During the test horses walked for 7 min, trotted for 10 min, cantered for 4 min, galloped for 1 min and recovered for 7 min.</AbstractText>Individual average heart rate during walk ranged from 42 to 175 beats/min, during trot from 89 to 207 beats/min, during canter from 141 to 269 beats/min, and during gallop from 191 to 311 beats/min. Individual beat-to-beat maximal heart rate ranged from 248 to 492 beats/min. Ventricular premature depolarisations were present in 81% of the horses: at rest (16%), during exercise (69%), and during recovery (2%). In 33% of the horses, broad QRS complexes with R-on-T morphology were found.</AbstractText>Exercising horses with lone AF frequently develop disproportionate tachycardia. In addition, QRS broadening and even R-on-T morphology is frequently found. QRS broadening may originate from ventricular ectopic foci or from aberrant intraventricular conduction, for example due to bundle branch block. This might explain the high number of complexes currently classified as ventricular premature depolarisations.</AbstractText>Prevalence of QRS broadening and especially R-on-T was very high in horses with AF and was found at low levels of exercise. These dysrhythmias are considered risk factors for the development of ventricular tachycardia and fibrillation and they might explain signs of weakness, collapse or sudden death that have been reported in horses with AF.</AbstractText>© 2012 EVJ Ltd.</CopyrightInformation> |
13,662 | Cardiopulmonary resuscitation: a historical perspective leading up to the end of the 19th century. | Social laws and religious beliefs throughout history underscore the leaps and bounds that the science of resuscitation has achieved from ancient times until today. The effort to resuscitate victims goes back to ancient history, where death was considered a special form of sleep or an act of God. Biblical accounts of resuscitation attempts are numerous. Resuscitation in the Middle Ages was forbidden, but later during Renaissance, any prohibition against performing cardiopulmonary resuscitation (CPR) was challenged, which finally led to the Enlightenment, where scholars attempted to scientifically solve the problem of sudden death. It was then that the various components of CPR (ventilation, circulation, electricity, and organization of emergency medical services) began to take shape. The 19th century gave way to hallmarks both in the ventilatory support (intubation innovations and the artificial respirator) and the open-and closed chest circulatory support. Meanwhile, novel defibrillation techniques had been employed and ventricular fibrillation described. The groundbreaking discoveries of the 20th century finally led to the scientific framework of CPR. In 1960, mouth-to-mouth resuscitation was eventually combined with chest compression and defibrillation to become CPR as we now know it. This review presents the scientific milestones behind one of medicine's most widely used fields. |
13,663 | Desipramine pretreatment improves sympathetic remodeling and ventricular fibrillation threshold after myocardial ischemia. | Abnormal increase in sympathetic nerve sprouting was responsible for the ventricular arrhythmogenesis after myocardial infarction. This study investigated whether the norepinephrine transporter inhibitor, desipramine, can modulate sympathetic remodeling and ventricular fibrillation threshold (VFT) after myocardial ischemia-reperfusion. Rats were administered desipramine (0.8 mg/kg, i.v.) before or after myocardial ischemia. VFT, infarct size, tyrosine hydroxylase (TH) and growth-associated protein 43 (GAP43)-positive nerve fibers were measured after one week. The VFT of preischemic treatment group was 11.0 ± 2.65 V and significantly higher than that of control ischemic group (7.2 ± 1.30 V, P < 0.05). Infarct size in the preischemic treatment group (23.3 ± 2.4%) was significantly lower than that in the control ischemic group (30.8 ± 1.3%, P < 0.05) and the delayed application group (27.1 ± 2.6%, P < 0.05). The density of TH and GAP43-positive nerve fibers in the control ischemic group was significantly higher than that in the other three groups (P < 0.05). The density of nerve fibers improved after desipramine treatment. Moreover, there was a negative correlation between the VFT and both TH and GAP43-positive nerve fiber density in the infarct border zone (P < 0.05). Desipramine treatment before acute myocardial ischemia can decrease infarct size, improve sympathetic remodeling, and increase VFT and electrical stability of ischemic hearts. Desipramine appears to cause myocardial ischemic preconditioning. |
13,664 | Metastasis to the right stellate ganglion and vagal nerve: pathological alterations causing sudden death. A case report. | Sudden death in a 66-year-old woman with squamous cell carcinoma of the oral cavity and exclusive metastatic involvement of the right stellate ganglion and right nerve vagus is reported. The patient also suffered from paroxysmal atrial fibrillation treated with quinidine. An autopsy showed exclusive metastases to the right stellate ganglion and vagus nerve, along with decreased nerve fibre density in the ventricular myocardium suggesting that Wallerian axon degeneration of cardiac fibres was responsible for sudden death.</Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Maffini</LastName><ForeName>F</ForeName><Initials>F</Initials><AffiliationInfo><Affiliation>Division of Pathology and Laboratory Medicine, European Institute of Oncology, G. Ripamonti 435, 20141 Milan, Italy. fausto.maffini@ieo.it</Affiliation></AffiliationInfo></Author><Author ValidYN="Y"><LastName>Pruneri</LastName><ForeName>G</ForeName><Initials>G</Initials></Author><Author ValidYN="Y"><LastName>Colombo</LastName><ForeName>N</ForeName><Initials>N</Initials></Author><Author ValidYN="Y"><LastName>Ansarin</LastName><ForeName>M</ForeName><Initials>M</Initials></Author><Author ValidYN="Y"><LastName>Grosso</LastName><ForeName>E</ForeName><Initials>E</Initials></Author><Author ValidYN="Y"><LastName>Bruschini</LastName><ForeName>R</ForeName><Initials>R</Initials></Author><Author ValidYN="Y"><LastName>Calabrese</LastName><ForeName>L</ForeName><Initials>L</Initials></Author><Author ValidYN="Y"><LastName>Chiesa</LastName><ForeName>F</ForeName><Initials>F</Initials></Author><Author ValidYN="Y"><LastName>Cipolla</LastName><ForeName>C</ForeName><Initials>C</Initials></Author><Author ValidYN="Y"><LastName>Pelosi</LastName><ForeName>G</ForeName><Initials>G</Initials></Author><Author ValidYN="Y"><LastName>Viale</LastName><ForeName>G</ForeName><Initials>G</Initials></Author></AuthorList><Language>eng</Language><PublicationTypeList><PublicationType UI="D002363">Case Reports</PublicationType><PublicationType UI="D016428">Journal Article</PublicationType></PublicationTypeList></Article><MedlineJournalInfo><Country>Italy</Country><MedlineTA>Acta Otorhinolaryngol Ital</MedlineTA><NlmUniqueID>8213019</NlmUniqueID><ISSNLinking>0392-100X</ISSNLinking></MedlineJournalInfo><CitationSubset>IM</CitationSubset><MeshHeadingList><MeshHeading><DescriptorName UI="D000368" MajorTopicYN="N">Aged</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D002294" MajorTopicYN="N">Carcinoma, Squamous Cell</DescriptorName><QualifierName UI="Q000150" MajorTopicYN="Y">complications</QualifierName><QualifierName UI="Q000556" MajorTopicYN="Y">secondary</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D003390" MajorTopicYN="N">Cranial Nerve Neoplasms</DescriptorName><QualifierName UI="Q000150" MajorTopicYN="Y">complications</QualifierName><QualifierName UI="Q000556" MajorTopicYN="Y">secondary</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D003645" MajorTopicYN="N">Death, Sudden</DescriptorName><QualifierName UI="Q000209" MajorTopicYN="Y">etiology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D005260" MajorTopicYN="N">Female</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D006801" MajorTopicYN="N">Humans</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D009062" MajorTopicYN="N">Mouth Neoplasms</DescriptorName><QualifierName UI="Q000473" MajorTopicYN="Y">pathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D010524" MajorTopicYN="N">Peripheral Nervous System Neoplasms</DescriptorName><QualifierName UI="Q000150" MajorTopicYN="Y">complications</QualifierName><QualifierName UI="Q000556" MajorTopicYN="Y">secondary</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D013233" MajorTopicYN="Y">Stellate Ganglion</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D014630" MajorTopicYN="Y">Vagus Nerve</DescriptorName></MeshHeading></MeshHeadingList><OtherAbstract Type="Publisher" Language="ita">Descriviamo un caso di morte improvvisa in una donna di 66 anni, affetta da carcinoma spinocellulare del cavo orale e con metastasi a livello del ganglio stellato di destra con coinvolgimento del nervo vago. La paziente era affetta inoltre da fibrillazione atriale parossistica (PAF) in terapia con quinidine. L'autopsia ha confermato le metastasi a livello del ganglio stellato di destra e del nervo vago omolaterale con contestuale riduzione della densità delle fibre cardiache del miocardio ventricolare, come osservato nella degenerazione Walleriana, causa della morte improvvisa. |
13,665 | Thromboembolism and antithrombotic therapy for heart failure in sinus rhythm: an executive summary of a joint consensus document from the ESC Heart Failure Association and the ESC Working Group on Thrombosis. | Chronic heart failure (HF) with either reduced or preserved left ventricular (LV) ejection fraction is common and remains an extremely serious disorder with a high mortality and morbidity. Many complications related to heart failure can be related to thrombosis. Epidemiological and pathophysiological data also link HF to an increased risk of thrombosis, leading to the clinical consequences of sudden death, stroke, systemic thromboembolism and/or venous thromboembolism. This executive summary of a joint consensus document of the Heart Failure Association (EHFA) of the European Society of Cardiology (ESC) and the ESC Working Group on Thrombosis reviews the published evidence, summarises 'best practice', and puts forward consensus statements that may help to define evidence gaps and assist management decisions in everyday clinical practice. In HF patients with atrial fibrillation, oral anticoagulation is clearly recommended, and the CHA2DS2-VASc and HAS-BLED scores should be used to determine the likely risk-benefit ratio (thromboembolism prevention versus risk of bleeding) of oral anticoagulation. In HF patients with reduced LV ejection fraction who are in sinus rhythm there is no evidence of an overall benefit of vitamin K antagonists (e.g. warfarin) on mortality, with risk of major bleeding. Whilst there is the potential for a reduction in ischaemic stroke, there is currently no compelling reason to routinely use warfarin for these patients. Risk factors associated with increased risk of thromboembolic events should be identified and decisions regarding use of anticoagulation individualised. Patient values and preferences are important determinants when balancing the risk of thromboembolism against bleeding risk. Novel oral anticoagulants that offer a different risk-benefit profile compared with warfarin may appear as an attractive therapeutic option, but this would need to be confirmed in clinical trials. |
13,666 | Lone atrial fibrillation in the young - perhaps not so "lone"? | To determine if pediatric patients with a history of lone atrial fibrillation (AF) have other forms of supraventricular tachycardia (SVT) that may potentially trigger AF.</AbstractText>A multicenter review of patients with lone AF who underwent electrophysiology (EP) study from 2006-2011 was performed.</AbstractText>age ≤21 years, normal ventricular function, structurally normal heart, history of AF, and EP study and/or ablation performed.</AbstractText>congenital heart disease or cardiomyopathy. Patient demographics, findings at EP study and follow-up data were recorded.</AbstractText>Eighteen patients met inclusion criteria. The mean age was 17.9 ± 2.2 years, weight was 82 ± 21 kg, body mass index was 27 ± 6, and 15 (83%) were males. Eleven (61%) were overweight or obese. Seven (39%) had inducible SVT during EP study: 5 atrioventricular nodal re-entry tachycardia (71%) and 2 concealed accessory pathways with inducible atrioventricular re-entry tachycardia (29%). All 7 patients with inducible SVT underwent radiofrequency ablation. There were no complications during EP study and/or ablation for all 18 patients. The mean follow-up was 1.7 ± 1.5 years and there were no recurrences in the 7 patients who underwent ablation. There were 2 recurrences of AF in patients with no other form of SVT during EP study.</AbstractText>Inducible SVT was found in 39% of pediatric patients undergoing EP study for lone AF. EP study should be considered for pediatric patients presenting with lone AF.</AbstractText>Copyright © 2013 Mosby, Inc. All rights reserved.</CopyrightInformation> |
13,667 | [Atrial fibrillation after coronary artery bypass surgery: possibilities of prevention]. | Atrial fibrillation occurs as a frequent complication after cardiac interventions. It can be found in 5% of all surgical patients, and it is far more common in cardiac (10% - 65% of patients) than in non-cardiac procedures. In a number of patients it remains asymptomatic, but may be accompanied by very severe symptoms of hypotension, heart failure, syncope, systemic or pulmonary embolism, perioperative myocardial infarction, cerebrovascular insult and increased operative mortality. Patients whose postoperative course is complicated by atrial fibrillation require longer hospitalization. Possible predisposing factors of this arrhythmia are numerous and are associated with surgery, extensive coronary heart disease and revascularization, and preoperative diseases. According to the recommendations of the European Society of Cardiology orally applied beta-blocker, amiodarone and sotalol can be used for prophylaxis of atrial fibrillation. Following the recommendations, treatment of postoperative atrial fibrillation should include beta-blockers, amiodarone, and in patients with heart failure and left ventricular dysfunction, digoxin. Due to the increased risk of stroke, an anticoagulant protection is necessary. Many studies have been conducted with results supporting the prophylactic use of amiodarone and beta-blockers, while the treatment with new agents such as magnesium, statins, omega-3 fatty acids and inhibitors of the renin-angiotensin-aldosterone system is still being investigated. |
13,668 | The risk stratification in atrial fibrillation. | Atrial fibrillation (AF) is the most common rhythm disorder and represents a major public health problem because it carries an increased risk of arterial thromboembolism and ischemic stroke. Because the absolute benefit of antithrombotic therapy depends on the underlying risk of stroke, an accurate stratification of patients' risk is needed to choose the appropriate antithrombotic strategy. Over the years, several stroke risk stratification models (RSMs) were developed based on the 'classic' risk factors for stroke such as increasing age, hypertension, diabetes mellitus, and left ventricular dysfunction. Among all RSMs, the CHADS(2) score is the most popular and used one thanks to its simplicity and endorsement in several widely promulgated practice guidelines. Despite its validation in large datasets and specific population of AF patients, it has many limitations, especially due to the non-inclusion of several proven risk factors for stroke and to the classification of a large number of patients in the intermediate risk category, so creating ambiguity over the most appropriate antithrombotic therapy. Thus, the CHA(2)DS(2)-VASc score was introduced and was demonstrated to perform better than the CHADS(2), even in a "real world" population of elderly AF patients. Recently, in view of the availability of new oral anticoagulant drugs, that can overcome the limitations of warfarin and allow a more personalized therapy, many efforts are being made to identify other possibilities to assess the thromboembolic risk in AF patients. It has been demonstrated that an increase in C-reactive protein and interleukin-6 and the presence of G20210A factor II gene polymorphism and hyper-homocysteinemia are independent risk factors for ischemic complications in AF patients. Even the presence of chronic renal disease and the daily AF burden, registered with implantable monitors, are associated with an increase risk of stroke. Finally, the assessment of thromboembolic risk should go hand in hand with the consideration of the risk of bleeding. For this purpose, it has been recently developed a practical bleeding risk score, the HAS-BLED, which was included in the last ESC guidelines for the risk stratification of AF patients before starting anticoagulant therapy. |
13,669 | Relation Between RR Intervals and Early Diastolic Mitral Annular Velocities in Atrial Fibrillation. | Irregular RR intervals in atrial fibrillation (AF) make beat-to-beat changes in left ventricular (LV) systolic performance. Early diastolic mitral annular velocity (E') is one of the well-established parameters for evaluating LV diastolic function. The relation between RR intervals and E's is unknown. The aim of this study was to observe the influence of continuous changes in RR interval on the parameter for diastolic function in AF.</AbstractText>Echocardiography was performed in 117 patients with AF. E' was adjusted for the effect of pre-preceding RR interval (RR-2) using the logarithmic equation between RR-2 and E'. The logarithmic equation between adjusted E' and preceding RR interval (RR-1) was calculated.</AbstractText>The slope in the relation between RR-1 and E' varied from -2.5 to 2.6. The slope was lower (more likely negative) in patients with higher ratio of early diastolic mitral flow velocity (E) to E' (r=-0.21, p=0.023), ischemic heart disease (IHD, r=0.21, p=0.026), and higher systolic blood pressure (r=-0.19, p=0.046). When patients were divided into these 3 groups on the basis of slope, the lowest slope group (<-0.55, n=39) was associated with higher E'/E (p=0.004) and IHD (p=0.018) compared with the highest slope group (>0.57, n=39). The slope with regards to the relationship between RR-2 and E' also varied from -3.4 to 3.1.</AbstractText>Changes in RR intervals had variable effects on E's according to clinical variables in AF.</AbstractText> |
13,670 | Spatial gradients in action potential duration created by regional magnetofection of hERG are a substrate for wavebreak and turbulent propagation in cardiomyocyte monolayers. | Spatial dispersion of action potential duration (APD) is a substrate for the maintenance of cardiac fibrillation, but the mechanisms are poorly understood. We investigated the role played by spatial APD dispersion in fibrillatory dynamics. We used an in vitro model in which spatial gradients in the expression of ether-à-go-go-related (hERG) protein, and thus rapid delayed rectifying K(+) current (I(Kr)) density, served to generate APD dispersion, high-frequency rotor formation, wavebreak and fibrillatory conduction. A unique adenovirus-mediated magnetofection technique generated well-controlled gradients in hERG and green fluorescent protein (GFP) expression in neonatal rat ventricular myocyte monolayers. Computer simulations using a realistic neonatal rat ventricular myocyte monolayer model provided crucial insight into the underlying mechanisms. Regional hERG overexpression shortened APD and increased rotor incidence in the hERG overexpressing region. An APD profile at 75 percent repolarization with a 16.6 ± 0.72 ms gradient followed the spatial profile of hERG-GFP expression; conduction velocity was not altered. Rotors in the infected region whose maximal dominant frequency was 12.9 Hz resulted in wavebreak at the interface (border zone) between infected and non-infected regions; dominant frequency distribution was uniform when the maximal dominant frequency was <12.9 Hz or the rotors resided in the uninfected region. Regularity at the border zone was lowest when rotors resided in the infected region. In simulations, a fivefold regional increase in I(Kr) abbreviated the APD and hyperpolarized the resting potential. However, the steep APD gradient at the border zone proved to be the primary mechanism of wavebreak and fibrillatory conduction. This study provides insight at the molecular level into the mechanisms by which spatial APD dispersion contributes to wavebreak, rotor stabilization and fibrillatory conduction. |
13,671 | Conduction recovery after electrical isolation of superior vena cava--prevalence and electrophysiological properties. | Superior vena cava (SVC) is an infrequent yet an important source of atrial fibrillation (AF). The data on SVC reconnection are limited.</AbstractText>Following pulmonary vein (PV) antrum isolation for AF, SVC isolation was systemically performed under angiographic and mapping guidance using 4-mm non-irrigated tip catheter. SVC reconnection could be evaluated in 76 consecutive patients (65 ± 9 years, 59 male) who underwent repeat AF ablation after 16 ± 16 months. SVC was isolated at the 1(st), 2(nd), 3(rd) and 4(th) AF ablation procedure in 63, 7, 5 and 1 patient by 7.3 ± 3.1 radiofrequency applications. SVC reconnection was observed in 56 patients (74%). In the majority, the conduction gap was located at the anterolateral SVC-right atrium (RA) junction. After re-isolation of SVC, 2/7 patients (29%) had reconnection at the following procedure. Among 63 patients who underwent PV and SVC isolation at the initial procedure, the prevalence of reconnection for PV and that for SVC were similar (53/63, 84% vs. 46/63, 73%; P=0.129). Dissociated activity, however, was more frequently observed in the PVs than in the SVC (47/63, 73% vs. 10/63, 16%; P<0.0001). During the procedure, AF initiation from a thoracic vein was identified in 19/63 patients (30%).</AbstractText>SVC reconnection is common after 1 or more previous isolation procedures undertaken for AF ablation. Its prevalence is similar to that of PV reconnection. The location of the conduction gap varies widely but is most frequently found at the anterolateral SVC-RA junction.</AbstractText> |
13,672 | Comparison of autonomic J-wave modulation in patients with idiopathic ventricular fibrillation and control subjects. | Although J-waves are seen in both patients with idiopathic ventricular fibrillation (IVF) and the general population, their genesis remains unclear. To assess the relationship between J-waves and autonomic tone we investigated the circadian variation of J-waves in individuals with and without IVF.</AbstractText>In study 1, we obtained resting 12-lead ECG and Holter ECG recordings in 258 individuals undergoing screening for heart disease. In 60 of these subjects (23.3%), we detected J-waves on Holter ECGs; 40 of them (66.7%) had shown no J-waves on 12-lead ECGs. In study 2, we measured the J-wave amplitude, heart rate (HR), and HR variability [high frequency (HF) and the ratio of low- to high-frequency (LF/HF)] on Holter ECGs recorded in 5 patients with IVF and 20 control subjects who had manifested J-waves. The J-wave amplitude increased at night and decreased during the day in both groups; it was significantly higher in the IVF patients (P<0.0001). In both groups, the J-wave amplitude showed a significant negative correlation with HR and LF/HF and a significant positive correlation with HF. The slope of the J/HR and J/(LF/HF) relationship was significantly steeper in the IVF patients.</AbstractText>The J-wave amplitude was more significantly influenced by the autonomic balance in IVF patients than in the controls. Autonomic J-wave modulation may yield important information on the genesis of J-waves.</AbstractText> |
13,673 | The best timing for defibrillation in shockable cardiac arrest. | High quality cardiopulmonary resuscitation (CPR, i.e. chest compressions and ventilations) and prompt defibrillation when appropriate (i.e. in ventricular fibrillation and pulseless ventricular tachycardia, VF/VT) are currently the best early treatment for cardiac arrest (CA). In cases of prolonged CA due to shockable rhythms, it is reasonable to presume that a period of CPR before defibrillation could partially revert the metabolic and hemodynamic deteriorations imposed to the heart by the no flow state, thus increasing the chances of successful defibrillation. Despite supporting early evidences in CA cases in which Emergency Medical System response time was longer than 5 minutes, recent studies have failed to confirm a survival benefit of routine CPR before defibrillation. These data have imposed a change in guidelines from 2005 to 2010. To take in account all the variables encountered when treating CA (heart condition before CA, time elapsed, metabolic and hemodynamic changes, efficacy of CPR, responsiveness to defibrillation attempt), it would be very helpful to have a real-time and non invasive tool able to predict the chances of defibrillation success. Recent evidences have suggested that ECG waveform analysis of VF, such as the derived Amplitude Spectrum Area, can fit the purpose of monitoring the CPR effectiveness and predicting the responsiveness to defibrillation. While awaiting clinical studies confirming this promising approach, CPR performed according to high quality standard and with minimal interruptions together with early defibrillation are the best immediate way to achieve resuscitation in CA due to shochable rhythms.. |
13,674 | Characterization of early repolarization during ajmaline provocation and exercise tolerance testing. | Early repolarization (ER) in the inferior electrocardiogram leads is associated with idiopathic ventricular fibrillation, but the majority of subjects with ER have a benign prognosis. At present, there are no risk stratifiers for asymptomatic ER.</AbstractText>To examine the response to ajmaline provocation and exercise in potentially high-risk subjects with ER and without a definitive cardiac diagnosis.</AbstractText>Electrocardiographic data were reviewed for ER at baseline and during ajmaline and exercise testing in 229 potentially high-risk patients (mean age 37.7±14.9 years; 55.9% men). ER was defined as J-point elevation in ≥2 consecutive leads and stratified by type, territory, J-point height, and ST-segment morphology.</AbstractText>Baseline ER was present in 26 (11.4%; 19 men) patients. During ajmaline provocation and exercise, there were no new ER changes. ER with rapidly ascending ST-segment and lateral ER consistently diminished. There were 7 patients with persistent ER during ajmaline and/or exercise. They were all men with inferior or inferolateral ER and horizontal/descending ST segment. Those with persistent ER during exercise were more likely to have a history of unexplained syncope than those in whom ER changes diminished (P<.01). Subtle nondiagnostic structural abnormalities were demonstrated in 3 of these patients.</AbstractText>ER with horizontal/descending ST-segment morphology in the inferior or inferolateral leads that persists during exercise is more common in patients with prior unexplained syncope and may identify patients at higher risk of arrhythmic events. ER that persists during ajmaline provocation and/or exercise may reflect underlying subtle structural abnormalities and should prompt further investigation.</AbstractText>Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,675 | Prolonged burst as a new method for cardioverter-defibrillator testing. | To find out whether it is possible to anaesthetize patients safely without analgesia and sedation, using burst pacing prolonged until the patient becomes unconscious.</AbstractText>One hundred and four patients undergoing implantation or reimplantation of a cardioverter-defibrillator were included. Patients randomized into Group B underwent prolonged burst pacing without analgesia and sedation. Patients in Group T underwent a T-wave shock under analgesia and sedation. Blood samples for measurement of serum neuron-specific enolase were taken before surgery and 6, 24, and 48 h after the procedure.</AbstractText>From the 104 patients, 51 were randomly assigned to Group B and 53 to Group T. Four patients from Group B were switched to Group T (ventricular fibrillation not induced by burst pacing). The clinical characteristics of both groups were similar. The mean total time of cardiac arrest was significantly longer in Group B (23.0 ± 4.4 s, median 22.7) vs. Group T (10.3 ± 3.0 s, median 10.0), P < 0.0001 (Mann-Whitney U-test). The effectiveness of both induction methods was similar (92.1% in Group B and 100% in Group T). The mean neuron-specific enolase levels after 6, 24, and 48 h were similar in Groups B and T (13.1 ± 6.3 and 11.6 ± 5.8 mg/L, 14.5 ± 7.5 and 13.4 ± 6.0 mg/L, and 14.9 ± 5.9 and 12.2 ± 6.0 mg/L, respectively) as were these levels compared with baseline neuron-specificenolase levels (14.0 ± 5.9 and 13.4 ± 4.0 mg/L, respectively), P = NS for all.</AbstractText>Despite a longer time of total cardiac arrest, prolonged burst pacing appears to be a safe and effective method for induction of ventricular fibrillation during cardioverter-defibrillator testing, which enables omission of analgesia and sedation or general anaesthesia.</AbstractText> |
13,676 | Temporary epicardial left ventricular and biventricular pacing improves cardiac output after cardiopulmonary bypass. | To evaluate, with different pacing modes, acute changes in left ventricular systolic function, obtained by continuous cardiac output thermodilution in various subsets of patients undergoing cardiopulmonary bypass surgery. Increments of mean arterial pressure and cardiac output were considered the end point.</AbstractText>Fifty cases electively submitted to cardiac surgery were analyzed. Isolated valve surgery 62%, coronary revascularization 30% and 8% mixed disease. Left ventricular ejection fraction was preserved in 50%,36% had moderate depression,(EF 36%-50%) whereas 14% had severe depression (EF < 35%). Left bundle branch block occurred in 18%. Preoperatively 84% were in sinus rhythm and 16% in atrial fibrillation. The different subgroups were analyzed for comparisons. Right atrial-right ventricular and right atrial-left ventricular pacing were employed in sinus rhytm. Biventricular pacing was also used in atrial fibrillation.</AbstractText>Right atrium-right ventricular pacing, decreased significantly mean arterial pressure and cardiac output (2.3%) in the overall population and in the subgroups studied. Right atrium-left ventricle, increased mean arterial pressure and cardiac output in 79% of patients and yielded cardiac output increments of 7.5% (0.40 l/m) in the low ejection fraction subgroup and 7.3% (0.43 l/m) in the left bundle branch block subset. In atrial fibrillation patients, left ventricular and biventricular pacing produced a significant increase in cardiac output 8.5% (0.39 l/min) and 11.6% (0.53 l/min) respectively. The dP/dt max increased significantly with both modes (p = 0.021,p = 0.028).</AbstractText>Right atrial-right ventricular pacing generated adverse hemodynamic effects. Right atrium-left ventricular pacing produced significant CO improvement particularly in cases with depressed ventricular function and left bundle branch block. The greatest increments were observed with left ventricular or biventricular pacing in atrial fibrillation with depressed ejection fraction.</AbstractText> |
13,677 | Ventricular tachyarrhythmias in rats with acute myocardial infarction involves activation of small-conductance Ca2+-activated K+ channels. | In vitro experiments have shown that the upregulation of small-conductance Ca(2+)-activated K(+) (SK) channels in ventricular epicardial myocytes is responsible for spontaneous ventricular fibrillation (VF) in failing ventricles. However, the role of SK channels in regulating VF has not yet been described in in vivo acute myocardial infarction (AMI) animals. The present study determined the role of SK channels in regulating spontaneous sustained ventricular tachycardia (SVT) and VF, the inducibility of ventricular tachyarrhythmias, and the effect of inhibition of SK channels on spontaneous SVT/VF and electrical ventricular instability in AMI rats. AMI was induced by ligation of the left anterior descending coronary artery in anesthetized rats. Spontaneous SVT/VF was analyzed, and programmed electrical stimulation was performed to evaluate the inducibility of ventricular tachyarrhythmias, ventricular effective refractory period (VERP), and VF threshold (VFT). In AMI, the duration and episodes of spontaneous SVT/VF were increased, and the inducibility of ventricular tachyarrhythmias was elevated. Pretreatment in the AMI group with the SK channel blocker apamin or UCL-1684 significantly reduced SVT/VF and inducibility of ventricular tachyarrhythmias (P < 0.05). Various doses of apamin (7.5, 22.5, 37.5, and 75.0 μg/kg iv) inhibited SVT/VF and the inducibility of ventricular tachyarrhythmias in a dose-dependent manner. Notably, no effects were observed in sham-operated controls. Additionally, VERP was shortened in AMI animals. Pretreatment in AMI animals with the SK channel blocker significantly prolonged VERP (P < 0.05). No effects were observed in sham-operated controls. Furthermore, VFT was reduced in AMI animals, and block of SK channels increased VFT in AMI animals, but, again, this was without effect in sham-operated controls. Finally, the monophasic action potential duration at 90% repolarization (MAPD(90)) was examined in the myocardial infarcted (MI) and nonmyocardial infarcted areas (NMI) of the left ventricular epicardium. Electrophysiology recordings showed that MAPD(90) in the MI area was shortened in AMI animals, and pretreatment with SK channel blocker apamin or UCL-1684 significantly prolonged MAPD(90) (P < 0.05) in the MI area but was without effect in the NMI area or in sham-operated controls. We conclude that the activation of SK channels may underlie the mechanisms of spontaneous SVT/VF and susceptibility to ventricular tachyarrhythmias in AMI. Inhibition of SK channels normalized the shortening of MAPD(90) in the MI area, which may contribute to the inhibitory effect on spontaneous SVT/VF and inducibility of ventricular tachyarrhythmias in AMI. |
13,678 | Thromboprophylaxis of elderly patients with AF in the UK: an analysis using the General Practice Research Database (GPRD) 2000-2009. | To assess use of thromboprophylaxis in UK general practise among patients with atrial fibrillation (AF); to investigate whether elderly patients are less likely to receive anticoagulation therapy than younger patients.</AbstractText>Retrospective cohort study</AbstractText>UK General Practice Research Database (GPRD) PATIENTS: Aged ≥60 years with a new diagnosis of AF (2000-2009).</AbstractText>None.</AbstractText>The main outcome measure was initiation of warfarin in the first year following diagnosis. Patients were categorised by stroke risk (CHADS(2) score) and bleeding risk (HAS-BLED score).</AbstractText>81 381 patients were identified (21% aged 60-69 years, 37% aged 70-79 years, 42% aged 80+ years). Patients aged 80+ years were significantly less likely to be initiated on warfarin than younger patients, adjusted for gender, practice and comorbidities; 32% of patients aged 80+ years received warfarin compared with 57% aged 60-69 years (p<0.0001), and 55% aged 70-79 years (p<0.0001). For all strata of CHADS(2)/HASBLED scores, patients aged 80+ years were significantly less likely to be treated with warfarin than younger patients. Logistic regression showed that female sex, low Basal Metabolic Index (BMI), age over 80 years, increasing HAS-BLED score and dementia were independently associated with reduced use of warfarin. Stroke/Transient Ischaemic Attack (TIA), hypertension, heart failure and left ventricular systolic dysfunction were associated with increased use. Patients with HAS-BLED>CHADS(2) were less likely to be initiated on warfarin. Higher CHADS(2) scores were associated with increased anticoagulation use.</AbstractText>Anticoagulation is being under-used in patients with AF aged 80+ years, even after taking into account increased bleeding risk in this age group.</AbstractText> |
13,679 | Reduced in-hospital survival rates of out-of-hospital cardiac arrest victims with obstructive pulmonary disease. | Out-of-hospital cardiac arrest (OHCA) due to sustained ventricular tachycardia/fibrillation (VT/VF) is common and often lethal. Patient's co-morbidities may determine survival after OHCA, and be instrumental in post-resuscitation care, but are poorly studied. We aimed to study whether patients with obstructive pulmonary disease (OPD) have a lower survival rate after OHCA than non-OPD patients.</AbstractText>We performed a community-based cohort study of 1172 patients with non-traumatic OHCA with ECG-documented VT/VF between 2005 and 2008. We compared survival to emergency room (ER), to hospital admission, to hospital discharge, and at 30 days after OHCA, of OPD-patients and non-OPD patients, using logistic regression analysis. We also compared 30-day survival of patients who were admitted to hospital, using multivariate logistic regression analysis.</AbstractText>OPD patients (n=178) and non-OPD patients (n=994) had comparable survival to ER (75% vs. 78%, OR 0.9 [95% CI: 0.6-1.3]) and to hospital admission (56% vs. 57%, OR 1.0 [0.7-1.4]). However, survival to hospital discharge was significantly lower among OPD patients (21% vs. 33%, OR 0.6 [0.4-0.9]). Multivariate regression analysis among patients who were admitted to hospital (OPD: n=100, no OPD: n=561) revealed that OPD was an independent determinant of reduced 30-day survival rate (39% vs. 59%, adjusted OR 0.6 [0.4-1.0, p=0.035]).</AbstractText>OPD-patients had lower survival rates after OHCA than non-OPD patients. Survival to ER and to hospital admission was not different between both groups. However, among OHCA victims who survived to hospital admission, OPD was an independent determinant of reduced 30-day survival rate.</AbstractText>Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,680 | Effect of defibrillation threshold testing on heart failure hospitalization or death in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy (MADIT-CRT). | Defibrillation threshold (DFT) testing is commonly practiced at the time of implantable cardioverter-defibrillator (ICD) implant. The clinical consequence of ICD shocks delivered during DFT testing is unknown.</AbstractText>The purpose of this study was to determine the impact of ICD shocks and ICD shock energy level delivered during DFT testing in patients enrolled in the Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) on clinical outcomes.</AbstractText>Patients who underwent DFT testing within 1 month of device implant were categorized by the number of ICD shocks delivered during DFT testing (0, 1, 2, ≥3 shocks) and according to high vs low (>20 J vs ≤20 J) energy ICD shocks. Clinical outcomes consisting of heart failure (HF) or death, death alone, HF alone, and ventricular tachycardia or ventricular fibrillation were analyzed in each group.</AbstractText>DFT testing was performed in 1,659 patients within 1 month of device implant (1 shock in 365 patients, 2 shocks in 896 patients, 3+ shocks in 398 patients). High-energy ICD shocks were delivered in 609 patients. Increasing number of ICD shocks during DFT testing was not associated with an increase risk for the primary end-point of HF or death or for any of the secondary end-points of HF alone, VT/VF alone, or death. Delivery of high vs low-energy ICD shocks was not associated with adverse clinical outcomes.</AbstractText>In patients with mild symptoms of HF, increasing number of ICD shocks and delivery of high energy ICD shocks during DFT testing was not associated with increased risk for HF or death or future VT/VF episodes.</AbstractText>Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,681 | Estimated glomerular filtration rate and proteinuria are associated with persistent form of atrial fibrillation: analysis in Japanese patients. | Several reports have identified that decline in renal function and presence of proteinuria are closely associated with incidence of atrial fibrillation (AF). However, it is still unclear whether these kidney-related markers are associated with the progression of AF from paroxysmal to persistent form.</AbstractText>Among the new patients who visited the Cardiovascular Institute Hospital between 2004 and 2010 (Shinken Database 2004-2010, n=15,227), both estimated glomerular filtration rate (eGFR) and proteinuria were measured in 1074 AF patients (paroxysmal/persistent 579/495, respectively), who were divided into tertiles of eGFR (the borderlines were 60.07 and 73.67 ml[min(-1)]1.73[m(-2)], respectively), and then further divided into the two categories with/without proteinuria. The average value of eGFR was lower (63.1 ml[min(-1)]1.73[m(-2)] vs. 68.8 ml[min(-1)]1.73[m(-2)], p<0.001) and the detection rate of proteinuria was higher (13.7% vs. 8.5%, p=0.006) in patients with persistent AF than in those with paroxysmal AF, respectively. In the multivariate analysis without parameters of echocardiography [left ventricular ejection fraction (LVEF) and left atrial dimension (LAD)], both eGFR and proteinuria were independently associated with persistent AF, but the association was abolished when the model included LAD and LVEF.</AbstractText>In the present analysis with cross-sectional design, both eGFR and proteinuria were apparently linked to the persistent form of AF, but their role in the pathogenesis does not seem to exceed the atrial stretch and remodeling, represented by LAD and LVEF.</AbstractText>Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
13,682 | Effect of isoprenaline chronic stimulation on APD restitution and ventricular arrhythmogenesis. | Isoprenaline (ISO) acts through β-adrenergic receptors to increase the intracellular Ca(2+), which has effects on action potential duration (APD) restitution and arrhythmogenesis. Thus, we investigated the effect of chronic stimulation with isoprenaline on APD restitution and ventricular tachyarrhythmias (VA) in the rabbit heart.</AbstractText>Rabbits were randomly selected to receive an injection of isoprenaline (ISO group) or an equal volume of 0.9% saline (CTL group). The S(1)-S(2) protocol (n=15) and S(1) dynamic pacing (n=15) were performed to construct APD restitution and to induce APD alternans or arrhythmia in 10 sites of Langendorff-perfused hearts. Compared with the same sites in the control group, long-term ISO administration (7 days) shortened the APD(90) and the effective refractory period (ERP), and greatly increased the spatial dispersion of APD and ERP (p<0.01). Compared to CTL group, the APD restitution curves were significantly changed (p<0.01) and showed increased spacial dispersion of maximal slope (S(max)) among each site in the ISO group (p<0.05). In induction of VA and APD alternans, the threshold of VA and alternans was both decreased in each site of the ISO group.</AbstractText>Chronic stimulation with ISO facilitated VA, possibly through the increased spatial dispersion of APD restitution.</AbstractText>Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
13,683 | The effects of a newly developed miniaturized mechanical chest compressor on outcomes of cardiopulmonary resuscitation in a porcine model*. | When the duration of cardiac arrest is prolonged, reperfusion of the vital organs by effective chest compression is the most important intervention for successful resuscitation. We investigated the effects of a newly developed miniaturized chest compressor on the outcomes of cardiopulmonary resuscitation.</AbstractText>Prospective, randomized, controlled experimental study.</AbstractText>University-affiliated animal research laboratory.</AbstractText>Thirty male domestic pigs.</AbstractText>Ventricular fibrillation was induced in 30 male domestic pigs weighing 35 ± 2 kg. Cardiopulmonary resuscitation was initiated after 7 mins of untreated ventricular fibrillation. The animals were randomized to receive mechanical chest compression with a miniaturized chest compressor, a LUCAS device or a Thumper device. After 5 mins of cardiopulmonary resuscitation, a 150-J defibrillation was delivered. If resuscitation was not successful, cardiopulmonary resuscitation was continued for 2 mins before the next defibrillation. The protocol was continued until successful resuscitation or for a total of 15 mins of cardiopulmonary resuscitation. The animals were observed for 72 hrs after resuscitation.</AbstractText>The miniaturized chest compressor generated significantly greater coronary perfusion pressure, end-tidal PCO2, carotid blood flow, and intrathoracic negative pressure, with significantly lower compression depth and fewer rib fractures when compared with both the LUCAS and Thumper devices. Both the miniaturized chest compressor and LUCAS devices required lower numbers of defibrillation for successful resuscitation when compared with the Thumper device. This was associated with lower prevalence of recurrent ventricular fibrillation and better postresuscitation myocardial and neurological function when compared with the Thumper device.</AbstractText>The miniaturized chest compressor improves hemodynamic efficacy and the success of cardiopulmonary resuscitation with significantly less injury, which is as effective as the LUCAS device. It may provide a new option for cardiopulmonary resuscitation.</AbstractText> |
13,684 | Single-chamber ICD, single-zone therapy in primary and secondary prevention patients: the simpler the better? | It is now well established that implantable cardioverter defibrillator (ICD) implantation reduces mortality in patients at increased risk of sudden cardiac death. However, the best programming parameters remain controversial. Our traditional policy has followed a simple approach in the vast majority of patients. In accordance with ICD programming in the major randomized clinical trials, we programmed a single high-rate, shock-only therapy zone. We aimed to demonstrate in this observational study that simple programming is not associated with higher shock rates or mortality when compared to other published studies.</AbstractText>Consecutive patients who underwent single-chamber ICD implantation with single-zone, high-rate programming at our institution between 1993 and 2008 were retrospectively studied. Data were collected prospectively in a database regarding details of ICD implantation, demographic data, and indication.</AbstractText>Three hundred thirty-two patients were included in our study, 31 % primary prevention and 68 % secondary prevention. Mean ejection fraction (EF) is 33.7 ± 15.3. Over a mean follow-up period of 62.5 ± 38.1 months, 135 patients experienced ICD shock (annualized event rate 7.7 %); 89 patients (26.8 %) appropriate shock in VT-ventricular fibrillation (VF), 68 patients (20.5 %) inappropriate shocks, and 22 patients (6.6 %) both. Twenty-nine patients (8.7 %) were reprogrammed to additional VT-ATP zones. Twenty-two (6.6 %) patients underwent heart transplantation. Sixty-two patients (18.6 %) died during follow-up, 43.6 % out of them due to cardiac cause, mainly progressive heart failure.</AbstractText>Our results show that simpler settings with single-zone, high-rate programming is associated with ICD shock rates and long-term mortality that does not appear to be worse when compared with contemporary studies which include multizone ICD programming with antitachycardia pacing activated.</AbstractText> |
13,685 | Commotio cordis, therapeutic hypothermia, and evacuation from a United States military base in Iraq. | Therapeutic hypothermia (TH) has been demonstrated to improve clinical outcomes after out-of-hospital ventricular fibrillation (VF) cardiac arrest. It remains unclear if TH can be safely and effectively used in the setting of traumatic arrest. Furthermore, the use of TH methods in the pre-hospital and transport environments remain poorly established and a domain of active investigation.</AbstractText>To describe a case of successful TH utilization after blunt trauma with commotio cordis and pulmonary contusion, and to describe the continuation of TH during international fixed-wing aeromedical transport.</AbstractText>A 33-year-old active duty soldier suffered blunt chest trauma and immediate VF arrest. He was successfully resuscitated with cardiopulmonary resuscitation and defibrillation attempts. Given his ensuing comatose post-arrest state, he was therapeutically cooled and subsequently evacuated from Iraq to Germany, with cooling maintenance established in flight without the availability of training or commercial cooling equipment. The patient exhibited an eventual excellent neurologic recovery. To utilize TH for this patient, military physicians with limited local resources employed a telemedical approach to obtain a hypothermia protocol to develop a successful treatment plan.</AbstractText>The patient's successful resuscitation suggests that care should not be withheld for blunt trauma patients without vital signs in the field if VF is present, until the differential diagnosis of commotio cordis has been considered.</AbstractText>Copyright © 2013 Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,686 | Clinical characteristics and outcomes of dilated phase of hypertrophic cardiomyopathy: report from the registry data in Japan. | A subset of patients with hypertrophic cardiomyopathy (HCM) has been reported to progress into dilated-HCM (D-HCM), characterized by left ventricular (LV) systolic dysfunction and cavity dilatation, resembling idiopathic dilated cardiomyopathy (DCM). We compared the characteristics, treatments, and outcomes in patients with heart failure (HF) due to D-HCM vs. DCM by using national registry data in Japan.</AbstractText>The Japanese Cardiac Registry of Heart Failure in Cardiology (JCARE-CARD) is a prospective observational study of patients hospitalized due to worsening HF with an average of 2.2 years of follow-up. Patients with D-HCM (n=41) were more likely to be male, have prior stroke, atrial fibrillation, and sustained ventricular tachycardia or ventricular fibrillation compared with DCM (n=486). Echocardiography demonstrated that D-HCM patients had smaller LV end-systolic diameter, higher ejection fraction, and greater wall thickness. Treatments for HF including angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, β-blocker, and spironolactone were similar between groups except for higher use of amiodarone, warfarin, and implantable cardioverter-defibrillator for D-HCM. Mortality was significantly higher in patients with D-HCM (29.7% vs. 14.4%; p<0.05). Sudden death tended to be higher also in D-HCM (8.1% vs. 2.6%; p=0.06), which, however, did not reach statistical significance.</AbstractText>HF patients with D-HCM had higher mortality risk than those with DCM. Effective management strategies are critically needed to be established for D-HCM.</AbstractText>Copyright © 2012 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
13,687 | Permanent pacing in patients with Chagas' disease. | Chagas' disease is an endemic disease in most Latin American countries. The cardiomyopathy associated with this condition often requires permanent pacing due to bradycardia. The aim of this study was to compare the indications for pacemaker implantation, intraoperative measurements, and long-term follow-up of patients with Chagas' cardiomyopathy (ChCM) and ischemic cardiomyopathy (ICM) referred for pacemaker implantation.</AbstractText>Retrospective study including consecutive patients with ChCM (Group 1) and ICM (Group 2), who underwent pacemaker implantation in a single center.</AbstractText>We analyzed 360 patients. Patients in Group 1 were younger (66.29 ± 7.01 vs 75.3 ± 7.11 years; P = 0.0001) and more often male (72% vs 60%; P = 0.05). Sinus node dysfunction (SND) was more prevalent in Group 1 (70% vs 52%; P = 0.03). Atrioventricular block was less prevalent in Group 1 (30% vs 48%; P = 0.04). No significant differences were found with respect to left ventricular ejection fraction (54.2 ± 9.1 vs 53.4 ± 8.2%; P = NS) and baseline QRS duration (119 ± 34 vs 108 ± 29 ms; P = NS). Right bundle branch block was more frequent in Group 1 (44% vs 12%; P = 0.0001), and left bundle branch block in Group 2 (6% vs 22%; P = 0.0001). Implantation time was longer in Group 1 (39 ± 19 vs 29 ± 13 minutes; P = 0.001) and was with higher atrial and ventricular pacing thresholds (1.4 ± 0.8 vs 1.0 ± 0.5 V; P = 0.001 and 1.2 ± 0.8 vs 0.6 ± 0.8 V; P = 0.001, respectively). During a follow-up of 42.8 ± 13.6 months, Group 1 had a higher incidence of new atrial fibrillation (34% vs 25.5%; P = 0.001), and there was a nonsignificant trend toward more displacements of the ventricular lead (6% vs 3.5%; P = 0.3). There were no deaths during the follow-up.</AbstractText>ChCM patients receiving pacemakers are younger and more frequently have SND compared to those with ICM. Pacemaker implant is longer in patients with ChCM disease and is with higher pacing thresholds. The incidence of new atrial fibrillation during the follow-up is significantly higher in patients with ChCM.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,688 | Current role of atrioventricular junction (AVJ) ablation. | Atrioventricular junction ablation with permanent pacemaker insertion is a highly effective treatment approach in patients with atrial fibrillation that is resistant to other treatment modalities, especially in the elderly or those with severe comorbidities. This effect likely reflects reversal of rapid ventricular rates and regularizing ventricular rates. There is increasing evidence that cardiac resynchronization therapy devices may be beneficial in selected populations after atrioventricular node ablation. The limitations of this approach include continued need for anticoagulation and lifelong pacemaker therapy. |
13,689 | Use of stored implanted cardiac defibrillator electrograms in catheter ablation of ventricular fibrillation. | Ventricular fibrillation (VF) can be abolished by targeting triggering ventricular ectopy, most often originating in the Purkinje network or right ventricular outflow tract (RVOT). This strategy relies upon the induction of premature ventricular complex (PVC) and/or VF. We sought to evaluate a VF ablation strategy that utilizes analysis of stored implantable cardioverter defibrillator (ICD) electrograms.</AbstractText>Eleven consecutive patients experiencing frequent VF episodes (≥three episodes in prior month) underwent electrophysiology study and ablation of VF triggers. PVC and VF induction was intentionally avoided or not possible in all of these patients. Pacemapping at likely sites for PVC triggers of VF using an analysis of the morphology and relative timing of the stored far- and near-field ICD electrograms of VF triggers was used to identify potential culprit locations. Radiofrequency energy was applied to these sites for ablation of the identified VF trigger.</AbstractText>Areas targeted for ablation included the left posterior fascicle (six), left anterior fascicle (three), RVOT (three) and left ventricular outflow tract (one); two patients had two separate triggers. Ablation was completed successfully without any complications. With a mean follow-up of 288 days (range 45-649), 10 patients are free of VF.</AbstractText>Ablation of VF triggers can be performed successfully with good short-term outcomes in patients with and without underlying heart disease. Use of stored ICD electrograms with a focus on likely target areas permit ablation without the need for PVC or VF induction. This can be useful when ectopy is not present for mapping and to avoid potentially dangerous initiation of multiple episodes of VF.</AbstractText>©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,690 | [Takotsubo cardiomyopathy]. | Takotsubo cardiomyopathy or "heart broken syndrome" or transient apical ballooning syndrome is an increasingly reported syndrome characterized by the fact that most patients are women aged over 65 years. The most common electrocardiographic changes are ST-segment elevation and negative T waves in precordial leads. Symptoms at onset are similar to those of acute myocardial infarction; the ventricular dysfunction is shaped like a takotsubo (a Japanese pot for fishing octopus), echocardiography and ventriculography show akinesia, hipokinesia or diskinesia (ballooning) of apical segments of left ventricle and hyperkinesia of the basal; the coronary arteries are normal angiographic; the dysfunction improves rapidly within a few weeks. Its origins are unclear, there are several pathophysiological theories, most sustained is a myocardial stunning secondary catecholamine-induced excess of intense physical or mental stress. There is no clear standard of treatment. In cases evolving with hemodynamic instability the use of beta agonist agents must be avoided, aortic balloon counterpulsation is preferable. The patient prognosis is usually good, reaching maximum mortality of 8%. In rare situations were reported complications such as acute pulmonary oedema, cardiogenic shock, acute mitral regurgitation, potentially fatal arrythmias ventricular fibrillation or torsades de pointes. In Cardiology Clinic of Cardiovascular Diseases Institute "Prof. Dr. George I.M. Georgescu" Iasi were hospitalized 4 cases with Takotsubo cardiomyopathy from 2008 to 2011. Their features are presented in this paper. The difference of prognosis and treatment between Takotsubo cardiomyopathy and acute myocardial infarction require an accurate diagnosis, the clinical hypothesis result only after knowledge the clinical and paraclinical peculiarities of this pathological entity. |
13,691 | Ventricular fibrillation coinciding with phentermine initiation. | A 70-year-old woman developed ventricular fibrillation subsequent to initiation of phentermine therapy. She was hospitalised and experienced recurrent ventricular fibrillation. During cardiac catheterisation, she was found to have a right coronary artery vasospasm, which resolved with intravenous nitroglycerin. Her phentermine was discontinued and the patient remained symptom free at last follow-up. |
13,692 | [Correlation between mitral regurgitation grading and left ventricular ejection fraction in elderly patients: a follow-up study]. | To analyze the correlation between mitral regurgitation grading and left ventricular ejection fraction in elderly patients (>60 years of age) in a 2-year follow-up.</AbstractText>A total of 455 patients with the diagnosis of at least mild mitral regurgitation by echocardiography were divided into ischemic mitral regurgitation (IMR) group and non-ischemic regurgitation (NIMR) group. The patients were followed up with echocardiography every 6 months and the data were analyzed at the end of 24 months.</AbstractText>Mitral regurgitation grade was inversely correlated with left ventricular ejection fraction (LVEF). Patients with moderate and severe IMR had a lower LVEF than those with NIMR (P<0.05). After adjustment for age, sex, body mass index, high blood pressure, diabetes, atrial fibrillation and cardiomyopathy, the mean LVEF at 2 years was lowered by 2.7% (1.4%-4.1%), 2.7% (1.3%-4.0%), and 5.2% (3.5%-6.9%) in mild, moderate and severe IMR patients, respectively (P<0.04), and by 3.2% (1.6%-4.8%), and 3.0% (1.4%-4.5%), and 1.7%(-0.5%-3.9%) in mild, moderate and severe NIMR patients (P=0.30).</AbstractText>The mean LVEF in IMR patients is significantly lowered compared to that in NIMR patients. The grade of mitral regurgitation is inversely correlated with the regurgitation area in IMR patients. Stratified management might help improve LVEF in severe IMR patients.</AbstractText> |
13,693 | Relationship between intrathoracic pressure and hemodynamics during cardiopulmonary resuscitation in a porcine model of prolonged cardiac arrest. | The influences of intrathoracic pressure (ITP) to hemodynamic and respiratory parameters during cardiopulmonary resuscitation (CPR) are confusing. In this research, we investigated the phasic changes of ITP during CPR and reveal the relationships among the hemodynamics, respiratory parameters, and ITP.</AbstractText>After 8 minutes of untreated ventricular fibrillation, which was induced in twenty intubated male domestic pigs, 12 minutes of 30: 2 CPR was performed. Continuous respiratory variables, hemodynamics, ITP and blood gas analysis were measured during CPR. After that, defibrillation was done and prognostic indicators after CPR was recorded.</AbstractText>Average ITP at baseline was -(14.1 ± 1.6) mmHg (1 mmHg = 0.133 kPa). When gasping inspirations were going on, it decreased sharply to near -50 mmHg. ITP fluctuated up and down quickly from near -20 mmHg to 20 mmHg when compressions were performed. These phasic changes became mild as the CPR was performed, the contrast of high and low ITP decreased to (12.95 ± 2.91) mmHg at the end of 12 minutes of CPR. Total alveolus minute volume decreased too, because of the decrease of compression and gasp related ventilations. Curve correlation was found between the tidal volume of compression and ITP: ITP = 607.33/(1 + 3134 × e(-0.58 × TV)), (e: natural constant, R(2) = 0.895). Negative correlations were found between the right atrial diastolic pressure and ITP (r = -0.753, P < 0.01); and positive correlations were found between the coronary perfusion pressure and ITP (r = 0.626, P < 0.01).</AbstractText>ITP is one of the key factors which can influence the prognosis of CPR. Correlations were found between the changes of ITP and the tidal volumes of compressions, right atrial diastolic pressure and coronary perfusion pressure during CPR. More positive ITP during compression and more negative during decompression were good to ventilation and perfusion.</AbstractText> |
13,694 | Aortic stenosis and mitral regurgitation as predictors of atrial fibrillation during 11 years of follow-up. | There is limited information about any association between the onset of atrial fibrillation (AF) and the presence of valvular disease.</AbstractText>We retrospectively examined 940 patients in sinus rhythm, examined by echocardiography in 1996. During 11 years of follow-up, we assessed the incidence of AF and outcome defined as valvular surgery or death, in relation to baseline valvular function. AS (aortic stenosis) severity at baseline examination was assessed using peak transaortic valve pressure gradient.</AbstractText>In univariate analysis, the risk of developing AF was related to AS (significant AS versus no significant AS; hazard ratio (HR) 3.73, 95% confidence interval (CI) 2.39-5.61, p<0.0001) and mitral regurgitation (MR) (significant MR versus no significant MR; HR 2.52, 95% CI 1.77-3.51, p<0.0001). Also the risk of valvular surgery or death was related to AS (HR 3.90, 95% CI 3.09-4.88, p<0.0001) and MR (HR 2.07, 95% CI 1.67-2.53, p<0.0001). In multivariate analyses, adjusting for sex, age, other valvular abnormalities, left ventricular ejection fraction and left atrial size - AS was independently related to both endpoints, whereas MR was not independently related to either endpoint.</AbstractText>AS, but not MR, was independently predictive of development of AF and combined valvular surgery or death. In patients with combined AS and MR, the grade of AS, more than the grade of MR, determined the risk of AF and combination of valvular surgery or death. Further studies using contemporary echocardiographic quantification of aortic stenosis are warranted to confirm these retrospective data based on peak transaortic valve pressure gradient.</AbstractText> |
13,695 | A Comparison of Selenium Concentrations between Congestive Heart Failure Patients and Healthy Volunteers. | Selenium (Se) is an essential trace element mainly obtained from seafood, meat, and cereals. Se deficiency has been identified as a major contributing factor in the pathogenesis of certain congestive heart failure (CHF) syndromes. Since there is controversy over the prevalence of Se deficiency among patient with CHF, the aim of this study was to assess the serum Se concentrations in patients with CHF and compared them with the Se status of healthy controls.</AbstractText>The study included 77 patients (age, 68.4 ± 10.4 years old; 40.3% female) and 73 healthy volunteers (64.9 ± 4.7 years old; 35.6% female). A complete medical/drug history and physical examination were performed for all patients and healthy volunteers. All patients had symptoms and signs of CHF and had a left ventricular ejection fraction (EF) of < 40% obtained by echocardiography. The Se concentration was assessed by atomic absorption spectrometer with the Graphite Tube Atomizer. The limit of measurement was 5 μg/L.</AbstractText>The Se concentrations in CHF patients did not show a significant difference from those of healthy controls (185.9 ± 781.2 μg/L vs. 123.3 ± 115.5 μg/L, respectively; p value = 0.499). There was no correlation between serum Se concentrations and EF in both the normal group and the patients with heart failure (p value = 0.96 and 0.99; r = 0.006 and 0.002 for patients and healthy volunteers, respectively).</AbstractText>In this study, serum Se levels in CHF patients were similar to those of controls and the Se concentrations did not correlate with the degree of left ventricular dysfunction.</AbstractText> |
13,696 | Internet-based device-assisted remote monitoring of cardiovascular implantable electronic devices: an evidence-based analysis. | The objective of this Medical Advisory Secretariat (MAS) report was to conduct a systematic review of the available published evidence on the safety, effectiveness, and cost-effectiveness of Internet-based device-assisted remote monitoring systems (RMSs) for therapeutic cardiac implantable electronic devices (CIEDs) such as pacemakers (PMs), implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices. The MAS evidence-based review was performed to support public financing decisions.</AbstractText><AbstractText Label="CLINICAL NEED: CONDITION AND TARGET POPULATION">Sudden cardiac death (SCD) is a major cause of fatalities in developed countries. In the United States almost half a million people die of SCD annually, resulting in more deaths than stroke, lung cancer, breast cancer, and AIDS combined. In Canada each year more than 40,000 people die from a cardiovascular related cause; approximately half of these deaths are attributable to SCD. Most cases of SCD occur in the general population typically in those without a known history of heart disease. Most SCDs are caused by cardiac arrhythmia, an abnormal heart rhythm caused by malfunctions of the heart’s electrical system. Up to half of patients with significant heart failure (HF) also have advanced conduction abnormalities. Cardiac arrhythmias are managed by a variety of drugs, ablative procedures, and therapeutic CIEDs. The range of CIEDs includes pacemakers (PMs), implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy (CRT) devices. Bradycardia is the main indication for PMs and individuals at high risk for SCD are often treated by ICDs. Heart failure (HF) is also a significant health problem and is the most frequent cause of hospitalization in those over 65 years of age. Patients with moderate to severe HF may also have cardiac arrhythmias, although the cause may be related more to heart pump or haemodynamic failure. The presence of HF, however, increases the risk of SCD five-fold, regardless of aetiology. Patients with HF who remain highly symptomatic despite optimal drug therapy are sometimes also treated with CRT devices. With an increasing prevalence of age-related conditions such as chronic HF and the expanding indications for ICD therapy, the rate of ICD placement has been dramatically increasing. The appropriate indications for ICD placement, as well as the rate of ICD placement, are increasingly an issue. In the United States, after the introduction of expanded coverage of ICDs, a national ICD registry was created in 2005 to track these devices. A recent survey based on this national ICD registry reported that 22.5% (25,145) of patients had received a non-evidence based ICD and that these patients experienced significantly higher in-hospital mortality and post-procedural complications. In addition to the increased ICD device placement and the upfront device costs, there is the need for lifelong follow-up or surveillance, placing a significant burden on patients and device clinics. In 2007, over 1.6 million CIEDs were implanted in Europe and the United States, which translates to over 5.5 million patient encounters per year if the recommended follow-up practices are considered. A safe and effective RMS could potentially improve the efficiency of long-term follow-up of patients and their CIEDs.</AbstractText>In addition to being therapeutic devices, CIEDs have extensive diagnostic abilities. All CIEDs can be interrogated and reprogrammed during an in-clinic visit using an inductive programming wand. Remote monitoring would allow patients to transmit information recorded in their devices from the comfort of their own homes. Currently most ICD devices also have the potential to be remotely monitored. Remote monitoring (RM) can be used to check system integrity, to alert on arrhythmic episodes, and to potentially replace in-clinic follow-ups and manage disease remotely. They do not currently have the capability of being reprogrammed remotely, although this feature is being tested in pilot settings. Every RMS is specifically designed by a manufacturer for their cardiac implant devices. For Internet-based device-assisted RMSs, this customization includes details such as web application, multiplatform sensors, custom algorithms, programming information, and types and methods of alerting patients and/or physicians. The addition of peripherals for monitoring weight and pressure or communicating with patients through the onsite communicators also varies by manufacturer. Internet-based device-assisted RMSs for CIEDs are intended to function as a surveillance system rather than an emergency system. Health care providers therefore need to learn each application, and as more than one application may be used at one site, multiple applications may need to be reviewed for alarms. All RMSs deliver system integrity alerting; however, some systems seem to be better geared to fast arrhythmic alerting, whereas other systems appear to be more intended for remote follow-up or supplemental remote disease management. The different RMSs may therefore have different impacts on workflow organization because of their varying frequency of interrogation and methods of alerts. The integration of these proprietary RM web-based registry systems with hospital-based electronic health record systems has so far not been commonly implemented. Currently there are 2 general types of RMSs: those that transmit device diagnostic information automatically and without patient assistance to secure Internet-based registry systems, and those that require patient assistance to transmit information. Both systems employ the use of preprogrammed alerts that are either transmitted automatically or at regular scheduled intervals to patients and/or physicians. The current web applications, programming, and registry systems differ greatly between the manufacturers of transmitting cardiac devices. In Canada there are currently 4 manufacturers—Medtronic Inc., Biotronik, Boston Scientific Corp., and St Jude Medical Inc.—which have regulatory approval for remote transmitting CIEDs. Remote monitoring systems are proprietary to the manufacturer of the implant device. An RMS for one device will not work with another device, and the RMS may not work with all versions of the manufacturer’s devices. All Internet-based device-assisted RMSs have common components. The implanted device is equipped with a micro-antenna that communicates with a small external device (at bedside or wearable) commonly known as the transmitter. Transmitters are able to interrogate programmed parameters and diagnostic data stored in the patients’ implant device. The information transfer to the communicator can occur at preset time intervals with the participation of the patient (waving a wand over the device) or it can be sent automatically (wirelessly) without their participation. The encrypted data are then uploaded to an Internet-based database on a secure central server. The data processing facilities at the central database, depending on the clinical urgency, can trigger an alert for the physician(s) that can be sent via email, fax, text message, or phone. The details are also posted on the secure website for viewing by the physician (or their delegate) at their convenience.</AbstractText>The research directions and specific research questions for this evidence review were as follows: 1. To identify the Internet-based device-assisted RMSs available for follow-up of patients with therapeutic CIEDs such as PMs, ICDs, and CRT devices. 2. To identify the potential risks, operational issues, or organizational issues related to Internet-based device-assisted RM for CIEDs. 3. To evaluate the safety, acceptability, and effectiveness of Internet-based device-assisted RMSs for CIEDs such as PMs, ICDs, and CRT devices. 4. To evaluate the safety, effectiveness, and cost-effectiveness of Internet-based device-assisted RMSs for CIEDs compared to usual outpatient in-office monitoring strategies. 5. To evaluate the resource implications or budget impact of RMSs for CIEDs in Ontario, Canada.</AbstractText>LITERATURE SEARCH: The review included a systematic review of published scientific literature and consultations with experts and manufacturers of all 4 approved RMSs for CIEDs in Canada. Information on CIED cardiac implant clinics was also obtained from Provincial Programs, a division within the Ministry of Health and Long-Term Care with a mandate for cardiac implant specialty care. Various administrative databases and registries were used to outline the current clinical follow-up burden of CIEDs in Ontario. The provincial population-based ICD database developed and maintained by the Institute for Clinical Evaluative Sciences (ICES) was used to review the current follow-up practices with Ontario patients implanted with ICD devices. SEARCH STRATEGY: A literature search was performed on September 21, 2010 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from 1950 to September 2010. Search alerts were generated and reviewed for additional relevant literature until December 31, 2010. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. INCLUSION CRITERIA: published between 1950 and September 2010; English language full-reports and human studies; original reports including clinical evaluations of Internet-based device-assisted RMSs for CIEDs in clinical settings; reports including standardized measurements on outcome events such as technical success, safety, effectiveness, cost, measures of health care utilization, morbidity, mortality, quality of life or patient satisfaction; randomized controlled trials (RCTs), systematic reviews and meta-analyses, cohort and controlled clinical studies. EXCLUSION CRITERIA: non-systematic reviews, letters, comments and editorials; reports not involving standardized outcome events; clinical reports not involving Internet-based device assisted RM systems for CIEDs in clinical settings; reports involving studies testing or validating algorithms without RM; studies with small samples (<10 subjects). OUTCOMES OF INTEREST: The outcomes of interest included: technical outcomes, emergency department visits, complications, major adverse events, symptoms, hospital admissions, clinic visits (scheduled and/or unscheduled), survival, morbidity (disease progression, stroke, etc.), patient satisfaction, and quality of life.</AbstractText>The MAS evidence review was performed to review available evidence on Internet-based device-assisted RMSs for CIEDs published until September 2010. The search identified 6 systematic reviews, 7 randomized controlled trials, and 19 reports for 16 cohort studies—3 of these being registry-based and 4 being multi-centered. The evidence is summarized in the 3 sections that follow. 1. Effectiveness of Remote Monitoring Systems of CIEDs for Cardiac Arrhythmia and Device Functioning.</b> In total, 15 reports on 13 cohort studies involving investigations with 4 different RMSs for CIEDs in cardiology implant clinic groups were identified in the review. The 4 RMSs were: Care Link Network® (Medtronic Inc,, Minneapolis, MN, USA); Home Monitoring® (Biotronic, Berlin, Germany); House Call 11® (St Jude Medical Inc., St Pauls, MN, USA); and a manufacturer-independent RMS. Eight of these reports were with the Home Monitoring® RMS (12,949 patients), 3 were with the Care Link® RMS (167 patients),</b> 1 was with the House Call 11® RMS (124 patients), and 1 was with a manufacturer-independent RMS (44 patients). All of the studies, except for 2 in the United States, (1 with Home Monitoring® and 1 with House Call 11®), were performed in European countries. The RMSs in the studies were evaluated with different cardiac implant device populations: ICDs only (6 studies), ICD and CRT devices (3 studies), PM and ICD and CRT devices (4 studies), and PMs only (2 studies). The patient populations were predominately male (range, 52%–87%) in all studies, with mean ages ranging from 58 to 76 years. One study population was unique in that RMSs were evaluated for ICDs implanted solely for primary prevention in young patients (mean age, 44 years) with Brugada syndrome, which carries an inherited increased genetic risk for sudden heart attack in young adults. Most of the cohort studies reported on the feasibility of RMSs in clinical settings with limited follow-up. In the short follow-up periods of the studies, the majority of the events were related to detection of medical events rather than system configuration or device abnormalities. The results of the studies are summarized below: The interrogation of devices on the web platform, both for continuous and scheduled transmissions, was significantly quicker with remote follow-up, both for nurses and physicians. In a case-control study focusing on a Brugada population–based registry with patients followed-up remotely, there were significantly fewer outpatient visits and greater detection of inappropriate shocks. One death occurred in the control group not followed remotely and post-mortem analysis indicated early signs of lead failure prior to the event. Two studies examined the role of RMSs in following ICD leads under regulatory advisory in a European clinical setting and noted: – Fewer inappropriate shocks were administered in the RM group. – Urgent in-office interrogations and surgical revisions were performed within 12 days of remote alerts. – No signs of lead fracture were detected at in-office follow-up; all were detected at remote follow-up. Only 1 study reported evaluating quality of life in patients followed up remotely at 3 and 6 months; no values were reported. Patient satisfaction was evaluated in 5 cohort studies, all in short term follow-up: 1 for the Home Monitoring® RMS, 3 for the Care Link® RMS, and 1 for the House Call 11® RMS. – Patients reported receiving a sense of security from the transmitter, a good relationship with nurses and physicians, positive implications for their health, and satisfaction with RM and organization of services. – Although patients reported that the system was easy to implement and required less than 10 minutes to transmit information, a variable proportion of patients (range, 9% 39%) reported that they needed the assistance of a caregiver for their transmission. – The majority of patients would recommend RM to other ICD patients. – Patients with hearing or other physical or mental conditions hindering the use of the system were excluded from studies, but the frequency of this was not reported. Physician satisfaction was evaluated in 3 studies, all with the Care Link® RMS: – Physicians reported an ease of use and high satisfaction with a generally short-term use of the RMS. – Physicians reported being able to address the problems in unscheduled patient transmissions or physician initiated transmissions remotely, and were able to handle the majority of the troubleshooting calls remotely. – Both nurses and physicians reported a high level of satisfaction with the web registry system. 2. Effectiveness of Remote Monitoring Systems in Heart Failure Patients for Cardiac Arrhythmia and Heart Failure Episodes.</b> Remote follow-up of HF patients implanted with ICD or CRT devices, generally managed in specialized HF clinics, was evaluated in 3 cohort studies: 1 involved the Home Monitoring® RMS and 2 involved the Care Link® RMS. In these RMSs, in addition to the standard diagnostic features, the cardiac devices continuously assess other variables such as patient activity, mean heart rate, and heart rate variability. Intra-thoracic impedance, a proxy measure for lung fluid overload, was also measured in the Care Link® studies. The overall diagnostic performance of these measures cannot be evaluated, as the information was not reported for patients who did not experience intra-thoracic impedance threshold crossings or did not undergo interventions. The trial results involved descriptive information on transmissions and alerts in patients experiencing high morbidity and hospitalization in the short study periods. 3. Comparative Effectiveness of Remote Monitoring Systems for CIEDs.</b> Seven RCTs were identified evaluating RMSs for CIEDs: 2 were for PMs (1276 patients) and 5 were for ICD/CRT devices (3733 patients). Studies performed in the clinical setting in the United States involved both the Care Link® RMS and the Home Monitoring® RMS, whereas all studies performed in European countries involved only the Home Monitoring® RMS. 3A. RANDOMIZED CONTROLLED TRIALS OF REMOTE MONITORING SYSTEMS FOR PACEMAKERS: Two trials, both multicenter RCTs, were conducted in different countries with different RMSs and study objectives. The PREFER trial was a large trial (897 patients) performed in the United States examining the ability of Care Link®, an Internet-based remote PM interrogation system, to detect clinically actionable events (CAEs) sooner than the current in-office follow-up supplemented with transtelephonic monitoring transmissions, a limited form of remote device interrogation. The trial results are summarized below: In the 375-day mean follow-up, 382 patients were identified with at least 1 CAE—111 patients in the control arm and 271 in the remote arm. The event rate detected per patient for every type of CAE, except for loss of atrial capture, was higher in the remote arm than the control arm. The median time to first detection of CAEs (4.9 vs. 6.3 months) was significantly shorter in the RMS group compared to the control group (P</i> < 0.0001). Additionally, only 2% (3/190) of the CAEs in the control arm were detected during a transtelephonic monitoring transmission (the rest were detected at in-office follow-ups), whereas 66% (446/676) of the CAEs were detected during remote interrogation. The second study, the OEDIPE trial, was a smaller trial (379 patients) performed in France evaluating the ability of the Home Monitoring® RMS to shorten PM post-operative hospitalization while preserving the safety of conventional management of longer hospital stays. Implementation and operationalization of the RMS was reported to be successful in 91% (346/379) of the patients and represented 8144 transmissions. In the RM group 6.5% of patients failed to send messages (10 due to improper use of the transmitter, 2 with unmanageable stress). Of the 172 patients transmitting, 108 patients sent a total of 167 warnings during the trial, with a greater proportion of warnings being attributed to medical rather than technical causes. Forty percent had no warning message transmission and among these, 6 patients experienced a major adverse event and 1 patient experienced a non-major adverse event. Of the 6 patients having a major adverse event, 5 contacted their physician. The mean medical reaction time was faster in the RM group (6.5 ± 7.6 days vs. 11.4 ± 11.6 days). The mean duration of hospitalization was significantly shorter (P</i> < 0.001) for the RM group than the control group (3.2 ± 3.2 days vs. 4.8 ± 3.7 days). Quality of life estimates by the SF-36 questionnaire were similar for the 2 groups at 1-month follow-up. 3B. RANDOMIZED CONTROLLED TRIALS EVALUATING REMOTE MONITORING SYSTEMS FOR ICD OR CRT DEVICES: The 5 studies evaluating the impact of RMSs with ICD/CRT devices were conducted in the United States and in European countries and involved 2 RMSs—Care Link® and Home Monitoring ®. The objectives of the trials varied and 3 of the trials were smaller pilot investigations. The first of the smaller studies (151 patients) evaluated patient satisfaction, achievement of patient outcomes, and the cost-effectiveness of the Care Link® RMS compared to quarterly in-office device interrogations with 1-year follow-up. Individual outcomes such as hospitalizations, emergency department visits, and unscheduled clinic visits were not significantly different between the study groups. Except for a significantly higher detection of atrial fibrillation in the RM group, data on ICD detection and therapy were similar in the study groups. Health-related quality of life evaluated by the EuroQoL at 6-month or 12-month follow-up was not different between study groups. Patients were more satisfied with their ICD care in the clinic follow-up group than in the remote follow-up group at 6-month follow-up, but were equally satisfied at 12- month follow-up. The second small pilot trial (20 patients) examined the impact of RM follow-up with the House Call 11® system on work schedules and cost savings in patients randomized to 2 study arms varying in the degree of remote follow-up. The total time including device interrogation, transmission time, data analysis, and physician time required was significantly shorter for the RM follow-up group. The in-clinic waiting time was eliminated for patients in the RM follow-up group. The physician talk time was significantly reduced in the RM follow-up group (P</i> < 0.05). The time for the actual device interrogation did not differ in the study groups. The third small trial (115 patients) examined the impact of RM with the Home Monitoring® system compared to scheduled trimonthly in-clinic visits on the number of unplanned visits, total costs, health-related quality of life (SF-36), and overall mortality. There was a 63.2% reduction in in-office visits in the RM group. Hospitalizations or overall mortality (values not stated) were not significantly different between the study groups. Patient-induced visits were higher in the RM group than the in-clinic follow-up group. THE TRUST TRIAL: The TRUST trial was a large multicenter RCT conducted at 102 centers in the United States involving the Home Monitoring® RMS for ICD devices for 1450 patients. The primary objectives of the trial were to determine if remote follow-up could be safely substituted for in-office clinic follow-up (3 in-office visits replaced) and still enable earlier physician detection of clinically actionable events. Adherence to the protocol follow-up schedule was significantly higher in the RM group than the in-office follow-up group (93.5% vs. 88.7%, P</i> < 0.001). Actionability of trimonthly scheduled checks was low (6.6%) in both study groups. Overall, actionable causes were reprogramming (76.2%), medication changes (24.8%), and lead/system revisions (4%), and these were not different between the 2 study groups. The overall mean number of in-clinic and hospital visits was significantly lower in the RM group than the in-office follow-up group (2.1 per patient-year vs. 3.8 per patient-year, P</i> < 0.001), representing a 45% visit reduction at 12 months. The median time from onset of first arrhythmia to physician evaluation was significantly shorter (P</i> < 0.001) in the RM group than in the in-office follow-up group for all arrhythmias (1 day vs. 35.5 days). The median time to detect clinically asymptomatic arrhythmia events—atrial fibrillation (AF), ventricular fibrillation (VF), ventricular tachycardia (VT), and supra-ventricular tachycardia (SVT)—was also significantly shorter (P</i> < 0.001) in the RM group compared to the in-office follow-up group (1 day vs. 41.5 days) and was significantly quicker for each of the clinical arrhythmia events—AF (5.5 days vs. 40 days), VT (1 day vs. 28 days), VF (1 day vs. 36 days), and SVT (2 days vs. 39 days). System-related problems occurred infrequently in both groups—in 1.5% of patients (14/908) in the RM group and in 0.7% of patients (3/432) in the in-office follow-up group. The overall adverse event rate over 12 months was not significantly different between the 2 groups and individual adverse events were also not significantly different between the RM group and the in-office follow-up group: death (3.4% vs. 4.9%), stroke (0.3% vs. 1.2%), and surgical intervention (6.6% vs. 4.9%), respectively. The 12-month cumulative survival was 96.4% (95% confidence interval [CI], 95.5%–97.6%) in the RM group and 94.2% (95% confidence interval [CI], 91.8%–96.6%) in the in-office follow-up group, and was not significantly different between the 2 groups (P</i> = 0.174). THE CONNECT TRIAL: The CONNECT trial, another major multicenter RCT, involved the Care Link® RMS for ICD/CRT devices in a15-month follow-up study of 1,997 patients at 133 sites in the United States. The primary objective of the trial was to determine whether automatically transmitted physician alerts decreased the time from the occurrence of clinically relevant events to medical decisions. The trial results are summarized below: </b> Of the 575 clinical alerts sent in the study, 246 did not trigger an automatic physician alert. Transmission failures were related to technical issues such as the alert not being programmed or not being reset, and/or a variety of patient factors such as not being at home and the monitor not being plugged in or set up. The overall mean time from the clinically relevant event to the clinical decision was significantly shorter (P</i> < 0.001) by 17.4 days in the remote follow-up group (4.6 days for 172 patients) than the in-office follow-up group (22 days for 145 patients). – The median time to a clinical decision was shorter in the remote follow-up group than in the in-office follow-up group for an AT/AF burden greater than or equal to 12 hours (3 days vs. 24 days) and a fast VF rate greater than or equal to 120 beats per minute (4 days vs. 23 days). Although infrequent, similar low numbers of events involving low battery and VF detection/therapy turned off were noted in both groups. More alerts, however, were noted for out-of-range lead impedance in the RM group (18 vs. 6 patients), and the time to detect these critical events was significantly shorter in the RM group (same day vs. 17 days). Total in-office clinic visits were reduced by 38% from 6.27 visits per patient-year in the in-office follow-up group to 3.29 visits per patient-year in the remote follow-up group. Health care utilization visits (N = 6,227) that included cardiovascular-related hospitalization, emergency department visits, and unscheduled clinic visits were not significantly higher in the remote follow-up group. The overall mean length of hospitalization was significantly shorter (P</i> = 0.002) for those in the remote follow-up group (3.3 days vs. 4.0 days) and was shorter both for patients with ICD (3.0 days vs. 3.6 days) and CRT (3.8 days vs. 4.7 days) implants. The mortality rate between the study arms was not significantly different between the follow-up groups for the ICDs (P</i> = 0.31) or the CRT devices with defribillator (P</i> = 0.46).</AbstractText>There is limited clinical trial information on the effectiveness of RMSs for PMs. However, for RMSs for ICD devices, multiple cohort studies and 2 large multicenter RCTs demonstrated feasibility and significant reductions in in-office clinic follow-ups with RMSs in the first year post implantation. The detection rates of clinically significant events (and asymptomatic events) were higher, and the time to a clinical decision for these events was significantly shorter, in the remote follow-up groups than in the in-office follow-up groups. The earlier detection of clinical events in the remote follow-up groups, however, was not associated with lower morbidity or mortality rates in the 1-year follow-up. The substitution of almost all the first year in-office clinic follow-ups with RM was also not associated with an increased health care utilization such as emergency department visits or hospitalizations. The follow-up in the trials was generally short-term, up to 1 year, and was a more limited assessment of potential longer term device/lead integrity complications or issues. None of the studies compared the different RMSs, particularly the different RMSs involving patient-scheduled transmissions or automatic transmissions. Patients’ acceptance of and satisfaction with RM were reported to be high, but the impact of RM on patients’ health-related quality of life, particularly the psychological aspects, was not evaluated thoroughly. Patients who are not technologically competent, having hearing or other physical/mental impairments, were identified as potentially disadvantaged with remote surveillance. Cohort studies consistently identified subgroups of patients who preferred in-office follow-up. The evaluation of costs and workflow impact to the health care system were evaluated in European or American clinical settings, and only in a limited way. Internet-based device-assisted RMSs involve a new approach to monitoring patients, their disease progression, and their CIEDs. Remote monitoring also has the potential to improve the current postmarket surveillance systems of evolving CIEDs and their ongoing hardware and software modifications. At this point, however, there is insufficient information to evaluate the overall impact to the health care system, although the time saving and convenience to patients and physicians associated with a substitution of in-office follow-up by RM is more certain. The broader issues surrounding infrastructure, impacts on existing clinical care systems, and regulatory concerns need to be considered for the implementation of Internet-based RMSs in jurisdictions involving different clinical practices.</AbstractText> |
13,697 | Relationship between left ventricular longitudinal deformation and clinical heart failure during admission for acute myocardial infarction: a two-dimensional speckle-tracking study. | Heart failure (HF) complicating acute myocardial infarction (MI) is an ominous prognostic sign frequently caused by left ventricular (LV) systolic dysfunction. However, many patients develop HF despite preserved LV ejection fractions. The aim of this study was to test the hypothesis that LV longitudinal function is a stronger marker of in-hospital HF than traditional echocardiographic indices.</AbstractText>A total of 548 patients with acute MIs were evaluated (mean age, 63.2 ± 11.7 years; 71.6% men). Within 48 hours of admission, comprehensive echocardiography with assessment of global longitudinal strain (GLS) was performed, along with measurements of N-terminal pro-brain natriuretic peptide.</AbstractText>A total 89 patients (16.2%) had in-hospital HF assessed by Killip class > 1 in whom GLS was significantly impaired compared with patients without in-hospital HF (Killip class 1) (-14.6 ± 3.3% vs -10.1 ± 3.5%, P < .0001). In stepwise multiple logistic regression analysis including age, known HF, three-vessel disease, involvement of the left anterior descending coronary artery, episodes of atrial fibrillation, renal function, N-terminal pro-brain natriuretic peptide, troponin T level, LV ejection fraction, wall motion score index, and diastolic dysfunction indices, GLS emerged as the strongest marker of clinical HF (odds ratio, 1.47; 95% confidence interval [CI], 1.33-1.62; P < .0001). GLS remained independently associated with in-hospital HF in patients with LV ejection fractions > 40% (odds ratio, 1.33; 95% CI, 1.14-1.54; P < .05) and improved the C-statistic over other important covariates significantly (0.87 [95% CI, 0.82-0.91] vs 0.82 [95% CI, 0.76-0.89], P = .02).</AbstractText>Global longitudinal function assessed by GLS is significantly impaired in patients with MIs with in-hospital HF, and multivariate analysis suggests that reduced GLS is the single most powerful marker of manifest LV hemodynamic deterioration in the acute phase of MI.</AbstractText>Copyright © 2012 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
13,698 | Burden of atrial fibrillation and poor rate control detected by continuous monitoring and the risk for heart failure hospitalization. | Atrial fibrillation (AF) on electrocardiogram has been identified as a risk factor for hospitalizations in patients with heart failure (HF). We investigated whether continuous AF monitoring can identify when patients with HF are at risk for hospitalization.</AbstractText>In this retrospective analysis of data from 4 studies enrolling patients with HF with cardiac resynchronization therapy defibrillator devices with ≥90 days of follow-up (n = 1561), patients were identified as having AF if they had ≥1 day of >5 minutes of AF and >1 hour of total AF during entire follow-up. In patients with AF, device recorded AF burden (AFb) and ventricular rate during AF (VRAF) over the last 30 days was classified on a monthly basis into 3 evaluation groups: (1) ≥1 day of high burden of paroxysmal AF (≥6 hours) or persistent AF (all 30 days with AFb >23 hours) with poor rate control (VRAF >90 beats/min), (2) ≥1 day of high burden of paroxysmal AF with good rate control (VRAF ≤ 90 beats/min), and (3) no days with high burden of AF (AFb <6 hours) or persistent AF with good rate control. Each group was compared with monthly evaluations in patients without AF using an Anderson-Gill model for occurrence of HF hospitalizations in the next 30 days.</AbstractText>Patients with AF (n = 519, 33%) have a greater risk (hazard ratio [HR] 2.0, P < .001) for impending HF hospitalizations during entire follow-up compared with patients with no AF. One day of high burden of paroxysmal AF with good rate control in the last 30 days increases risk for HF hospitalization in the next 30 days (HR 3.4, P < .001). The risk increases further (HR 5.9, P < .001) with 1 day of poor rate control during persistent AF or high burden paroxysmal AF in last 30 days.</AbstractText>Evaluation of AFb and rate control information on a monthly basis can identify patients at risk for HF hospitalization in the next 30 days.</AbstractText>Copyright © 2012 Mosby, Inc. All rights reserved.</CopyrightInformation> |
13,699 | Regionalization of post-cardiac arrest care: implementation of a cardiac resuscitation center. | Guidelines recommend standardized treatment of post-cardiac arrest patients to improve outcomes. However, the infrastructure, resources, and personnel required to meet the complex needs of cardiac arrest victims remain a barrier to care. Given that regionalization of time-dependent high-acuity illness is an emerging paradigm, the aim of the present study was to develop and implement a regionalized approach to post-cardiac arrest care.</AbstractText>We performed a prospective observational study on all patients treated in a regionalized clinical pathway from November 2007 through June 2011. All patients were enrolled after admission to an urban academic medical center. Clinical data including arrest and treatment variables, complications, and outcome were collected on consecutive patients with the use of a preformatted standard data collection tool using Utstein criteria.</AbstractText>A total of 220 patients were enrolled; 127 (58%) patients were local direct admissions from our community, and 93 (42%) were transferred from 1 of 24 outlying referral hospitals. One hundred six (48%, 95% CI 38%-53%) patients survived to hospital discharge. The primary outcome of hospital survival with good neurologic function was observed in 94 (43%, 95% CI 32%-48%). There was no difference in survival with good neurologic outcome among local and referred patients. Overall 1-year survival was 44% (95% CI 38%-51%). Among patients discharged from the hospital with good neurologic function, 93% (95% CI 85%-97%) remained alive at 1 year.</AbstractText>Development of a regionalized approach to post-cardiac arrest care using previously established referral relationships is feasible, and implementation of such an approach was clinically effective in our region.</AbstractText>Copyright © 2012 Mosby, Inc. All rights reserved.</CopyrightInformation> |
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