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12,600 | Susceptibility to life-threatening ventricular arrhythmias in an animal model of paradoxical sleep deprivation. | According to some reports regarding the increase of cardiac events following sleep deprivation, our study was conducted to clarify the effects of rapid eye movement (REM) sleep deprivation on susceptibility to lethal ventricular arrhythmias in rat.</AbstractText>The animal groups included the control group; the sham 48 and sham 72 groups (without sleep deprivation); and the test 48 and test 72 groups, who experienced REM sleep deprivation for 48h and 72h, respectively. For induction of cardiac arrhythmia, aconitine was infused via the tail vein of the animals.</AbstractText>After 72h of REM sleep deprivation, the blood pressure (BP) levels and the QTc interval of the electrocardiogram (ECG) were significantly increased (P<.05 and P<.01, respectively). However, the sleep deprivation had no significant effect on the heart rate (HR), myocardial oxygen consumption index, and plasma corticosterone level. Furthermore, sleep deprivation increased the latency times of premature ventricular contraction (PVC), ventricular tachycardia (VT), and also the PVC number; however, it did not increase the number, duration, and severity of VT and ventricular fibrillation (VF).</AbstractText>Our findings suggest that 72h of REM sleep deprivation is associated with increased risk for hypertension and QT interval prolongation under nonstressful conditions; however, it does not increase the susceptibility to lethal ventricular arrhythmia in rat.</AbstractText>Copyright © 2013 Elsevier B.V. All rights reserved.</CopyrightInformation> |
12,601 | Epinephrine for prehospital cardiac arrest with non-shockable rhythm. | Cardiopulmonary arrest research and guidelines have generally focused on the treatment and management of ventricular fibrillation and pulseless ventricular fibrillation (electrical shockable rhythms). Less investigation has been done on the subpopulation of cardiopulmonary arrest victims that present with non-shockable rhythms. In a new paper, Goto, Maeda, and Goto present evidence that early use of epinephrine for treatment is associated with better survival with functional outcome. While there is a lack of evidence to support epinephrine for management of cardiopulmonary arrest presenting with initial shockable rhythms (presumed primary cardiac origin), there is now evidence that epinephrine may potentially benefit those presenting with non-shockable cardiopulmonary arrest (presumed heterogeneous origins). Further research on non-shockable rhythm cardiopulmonary arrest is needed to understand the subpopulation and develop better treatment guidelines. |
12,602 | [Prophylactic use of VFS in patients with coronary artery disease in the perioperative coronary artery bypass grafting]. | Tachyarrhythmias (TA) - dangerous postoperative complications of coronary artery bypass grafting, threatening the lives of patients and found, according to different authors, in 13-40% of cases. VFS - an antiarrhythmic drug that belongs to a class 1C, is effective in the treatment and prevention of a variety of cardiac arrhythmias. The aim of the work was to study the clinical efficacy of VFS CHD patients with a history of tachyarrhythmias during the perioperative period of coronary bypass surgery, as well as its comparison with other antiarrhythmic drug (amiodarone). Clinical efficacy was evaluated in 218 patients with coronary heart disease at baseline with a history of tachyarrhythmia (paroxysmal atrial fibrillation or premature ventricular high grade (IV and V class on classification of Lown B. and Wolf M. in the modification of Ryan M.). Shown that the VFS is more effective than amiodarone, both in paroxysmal atrial fibrillation and ventricular arrhythmias when high gradation. |
12,603 | Left atrial appendage dysfunction in a patient with premature ventricular contractions - a risk factor for stroke? | A 16-year-old female with ventricular dysfunction and frequent ventricular arrhythmia presented with a cardioembolic stroke. Prior electrophysiology study and ablation was performed for ventricular tachycardia (VT). For remaining ventricular ectopy, the patient was maintained on carvedilol and mexiletine. After one year on this regimen, she presented with an acute stroke. Transesophageal echocardiography revealed no evidence of an intracardiac or ventricular thrombus but demonstrated markedly decreased left atrial appendage (LAA) flow velocity worsened during frequent premature ventricular contractions (PVC). In the absence of atrial fibrillation (AF), the LAA dysfunction was considered secondary to the frequent PVCs and was thought to be the underlying cause for the stroke. We present this case to highlight a potential under recognized association between LAA dysfunction and ventricular arrhythmia, similar to that observed with atrioventricular dyssynchronous pacing. |
12,604 | Perioperative Diastolic Dysfunction: A Comprehensive Approach to Assessment by Transesophageal Echocardiography. | Left ventricular diastolic dysfunction (LVDD) has only recently been recognized as an important determinant of perioperative morbidity. Intraoperative echocardiographers have been slow to adopt assessment of LVDD into clinical practice. This has been partly attributable to the complex measurements required to characterize LVDD, which are in turn related to how our understanding of diastole has evolved. Additionally, the lack of effective therapeutic options has left many wondering whether it is worthwhile to characterize this pathology in the first place. However, therapies are developed more rapidly once a problem can be identified reliably. The assessment of LVDD is centered on how effectively the left ventricle can fill. Diastolic dysfunction affects intraventricular pressures and stiffness, which in turn affect the pressure relationship between the left atrium and the left ventricle thereby affecting transmitral flow. Since echocardiography can enable the measurement of flow velocities, transmitral diastolic filling flow patterns provide robust information on diastolic function. The impact of abnormal diastolic function on left atrial pressure has consequences for pulmonary venous flow, which can also be measured with echocardiography. However, given the limitations of flow velocity, direct measurement of tissue velocity can significantly improve the characterization of diastolic dysfunction. The evolution of Doppler and speckle-based methods of assessing tissue motion have vastly improved our understanding of diastolic function. With the development of simpler algorithms for categorization, and their gradual adoption by perioperative echocardiographers, LVDD should be better diagnosed and treated to improve postoperative outcomes. |
12,605 | Electrophysiological and hemodynamic effects of vernakalant and flecainide during cardiac resynchronization in dyssynchronous canine hearts. | Patients with heart failure and left bundle branch block (LBBB) are frequently treated with biventricular pacing (BiVP). Approximately one-third of them suffer from atrial fibrillation. Pharmacological conversion of atrial fibrillation is performed with drugs that slow ventricular conduction, but the effects of these drugs on the benefit of BiVP are poorly understood.</AbstractText>Experiments were performed in dogs with chronic LBBB, investigating the effects of Vernakalant and Flecainide (n = 6 each) on hemodynamics and electrophysiology during epicardial (EPI) and endocardial BiVP. The degree of dyssynchrony and conduction slowing was quantified using QRS width and EPI electrical mapping.</AbstractText>Compared with LBBB, EPI and endocardial BiVP reduced QRS duration by 7% ± 9% (P < 0.05 compared with LBBB) and 20% ± 13% (P < 0.05 compared with LBBB, P < 0.05 between modes), respectively. During BiVP, the administration of Vernakalant and Flecainide increased QRS duration by 20% ± 14% (P < 0.05 compared with predrug BiVP) and 34% ± 10% (P < 0.05 compared with predrug BiVP, P < 0.05 between drugs). left ventricular (LV) dP/dtmax decreased by 16% ± 8% (P < 0.05 compared with predrug BiVP) during Vernakalant and by 14% ± 15% (P < 0.05 compared with predrug BiVP) during Flecainide. The drugs did not affect the relative changes in QRS width and LV dP/dtmax induced by BiVP.</AbstractText>Vernakalant and Flecainide decrease contractility, slow myocardial conduction velocity, and increase activation time. The electrical and hemodynamic benefits of BiVP are not altered by the drugs.</AbstractText> |
12,606 | Effects of endothelin-1 chronic stimulation on electrical restitution, beat-to-beat variability of repolarization, and ventricular arrhythmogenesis. | Chronically elevated levels of endothelin-1 (ET-1) have been detected in several cardiovascular diseases. In this study, we investigated the chronic effects of ET-1 on the electrophysiological characteristics expected to influence the genesis and maintenance of ventricular arrhythmia (VA). Rabbits were randomized to ET-1 (ET-1 group) or 0.9% saline (control group) for 2 weeks. The S1-S2 protocol and S1-S1 dynamic pacing were performed to assess the action potential duration restitution (APDR) and to induce APD alternans or VA in 4 sites of Langendorff-perfused rabbit hearts. The beat-to-beat variability of repolarization was quantified as short-term variability and long-term variability. Compared with the control group, chronic ET-1 administration significantly prolonged QT intervals, APD at 90% repolarization (APD₉₀), and effective refractory period (ERP), steepened the maximum slopes of the APDR curve, decreased the ERP/APD₉₀ ratio, and increased the spatial dispersions of APD₉₀, ERP, and maximum slopes (P < 0.05 for all). Moreover, chronic ET-1 administration markedly increased the short-term variability and long-term variability (P < 0.01 for all). APD alternans occurred in both groups, but the threshold of APD alternans was decreased at all sites in the ET-1 group (P < 0.01 for all). We also observed that chronic ET-1 stimulation significantly increased the incidence and duration of the VA episodes. These results suggest that chronic stimulation with ET-1 facilitated VA by steepening the APDR curve and increasing the spatial dispersion of APDR and beat-to-beat variability of repolarization. |
12,607 | Rationale and design of a randomized trial on the impact of aldosterone antagonism on cardiac structure and function in diabetic cardiomyopathy. | Development of a cardiomyopathy in diabetes mellitus is independent of traditional risk factors, with no clinical trials targeting specific therapeutic interventions. Myocardial fibrosis is one of the key mechanisms and aldosterone is a key mediator of myocardial fibrosis. We propose that aldosterone antagonism will improve cardiac function. We aim to evaluate the efficacy of selective aldosterone receptor antagonism with eplerenone added to optimal medical treatment in improving cardiac structure and function in diabetic cardiomyopathy. We will randomize 130 patients with type 2 diabetes mellitus, stable metabolic control and impaired left ventricular (LV) systolic or diastolic function, to either eplerenone (target dose 50mg) or matching placebo, in addition to optimal medical therapy for 12 months. The primary endpoints are changes in LV systolic and diastolic function, measured by echocardiographic 2-dimensional speckle tracking strain and strain rate and tissue Doppler imaging. The secondary endpoints include changes in echocardiographic markers and plasma biomarkers of collagen turnover; left atrial dimensions and function, incidence of atrial fibrillation and changes in exercise capacity and dyspnea score. The present study will assess whether specific aldosterone antagonism with eplerenone in addition to standard therapy will prevent progression or reverse cardiac dysfunction in diabetic cardiomyopathy using sensitive, robust and quantifiable echocardiographic measures that allow early detection of change. The study may offer a new direction in the management of this condition.</AbstractText>ACTRN12610001063000.</AbstractText> |
12,608 | Cerebral protection against left ventricular thrombus during transcatheter aortic valve replacement in a patient with critical aortic stenosis. | Transcatheter aortic valve replacement is an increasingly common treatment of critical aortic stenosis. Many aortic stenosis patients have concomitant left ventricular dysfunction, which can instigate the formation of thrombus resistant to anticoagulation. Recent trials evaluating transcatheter aortic valve replacement have excluded patients with left ventricular thrombus. We present a case in which an 86-year-old man with known left ventricular thrombus underwent successful transcatheter aortic valve replacement under cerebral protection. |
12,609 | Ventricular fibrillation cardiac arrest due to 5-fluorouracil cardiotoxicity. | The antimetabolite chemotherapeutic agent 5-fluorouracil is used to treat a variety of cancers. Although 5-fluorouracil is generally well tolerated, its toxicity profile includes potential cardiac ischemia, vasospasm, arrhythmia, and direct myocardial injury. These actual or potential toxicities are thought to resolve upon cessation of the medication; however, information about the long-term cardiovascular effects of therapy is not sufficient. We present the case of a 58-year-old man who had 2 ventricular fibrillation cardiac arrests, with evidence of coronary vasospasm and myocarditis, on his 4th day of continuous infusion with 5-fluorouracil. External defibrillation and cessation of the 5-fluorouracil therapy resolved the patient's electrocardiographic abnormalities. In addition to reporting the clinical manifestations of 5-fluorouracil-associated cardiotoxicity in our patient, we discuss management challenges in patients who develop severe 5-fluorouracil-induced ventricular arrhythmias. |
12,610 | Rapid growth of left atrial myxoma after radiofrequency ablation. | Atrial myxoma is the most common benign tumor of the heart, but its appearance after radiofrequency ablation is very rare. We report a case in which an asymptomatic, rapidly growing cardiac myxoma arose in the left atrium after radiofrequency ablation. Two months after the procedure, cardiovascular magnetic resonance, performed to evaluate the right ventricular anatomy, revealed a 10 × 10-mm mass (assumed to be a thrombus) attached to the patient's left atrial septum. Three months later, transthoracic echocardiography revealed a larger mass, and the patient was diagnosed with myxoma. Two days later, a 20 × 20-mm myxoma weighing 37 g was excised. To our knowledge, the appearance of an atrial myxoma after radiofrequency ablation has been reported only once before. Whether tumor development is related to such ablation or is merely a coincidence is uncertain, but myxomas have developed after other instances of cardiac trauma. |
12,611 | Periodic breathing with no heart beat. | A protocol was originally designed to study breathing control during and following cardiac arrest in humans, taking advantage of the period of pulseless ventricular fibrillation (PVF) produced while testing a newly implanted cardioverter-defibrillator device. A patient aged in his 60s with New York Heart Association class III heart failure (HF) (left ventricular ejection fraction of 25%) who was originally part of this study displayed permanent periodic breathing (PB) and was then excluded from the final data analysis; his response is presented in this report. The 8- to 9-s PVF was incidentally produced during the ascending phase of a PB cycle, followed by another 12-s recovery period of low BP. PVF and its recovery had no effect on PB characteristics (period or amplitude). This occurred despite a profound change in Paco2, cerebral blood flow, and perfusion of the carotid bodies. It is concluded that PB in patients with HF could be produced by primary oscillations originating from the central pattern generator. |
12,612 | Seasonal variation in the frequency of sudden cardiac death and ventricular tachyarrhythmia in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy: the effect of meteorological factors. | Sudden cardiac death (SCD) is the most catastrophic presentation in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C).</AbstractText>To investigate the seasonal variations in the frequency of SCD and ventricular tachyarrhythmia in patients with AVRD/C and to elucidate the meteorological factors that trigger these events.</AbstractText>From 1998 to 2012, we enrolled 88 consecutive patients with ARVD/C from Taipei City. The cohort included 20 living patients who received implantable cardioverter-defibrillator (ICD) and 68 autopsied patients with SCD from the Taiwan National Forensic Institute registry. The baseline clinical characteristics, seasonal distribution, and associated meteorological factors were explored to predict the occurrences of events, which include appropriate ICD interventions and SCD.</AbstractText>There were 106 events, including 38 (35.8%, 1.9 episodes per patient) appropriate ICD interventions in living patients with ARVD/C and 68 (64.2%) SCD events. The seasonal peak occurred predominantly in summer (P < .05) in both groups. For meteorological factors, the onset of event was associated with higher average daily temperature and longer sunshine duration. The variation in humidity within 3 days of events was significantly increased. After multivariate logistic regression analysis, higher average daily temperature and larger variation in humidity were associated with increase in events (odds ratio 1.23, 95% confidence interval 1.16-1.31, P < .001, and odds ratio 1.19, 95% confidence interval 1.15-1.23, P < .001, respectively).</AbstractText>There was seasonal variation with a summer peak in the occurrence of ventricular arrhythmias and SCD in patients with ARVD/C. Meteorological factors including higher temperature and larger variation in humidity within 3 days of events were independently associated with the development of events.</AbstractText>© 2013 Heart Rhythm Society Published by Heart Rhythm Society All rights reserved.</CopyrightInformation> |
12,613 | Regional myocardial sympathetic denervation predicts the risk of sudden cardiac arrest in ischemic cardiomyopathy. | The PAREPET (Prediction of ARrhythmic Events with Positron Emission Tomography) study sought to test the hypothesis that quantifying inhomogeneity in myocardial sympathetic innervation could identify patients at highest risk for sudden cardiac arrest (SCA).</AbstractText>Left ventricular ejection fraction (LVEF) is the only parameter identifying patients at risk of SCA who benefit from an implantable cardiac defibrillator (ICD).</AbstractText>We prospectively enrolled 204 subjects with ischemic cardiomyopathy (LVEF ≤35%) eligible for primary prevention ICDs. Positron emission tomography (PET) was used to quantify myocardial sympathetic denervation ((11)C-meta-hydroxyephedrine [(11)C-HED]), perfusion ((13)N-ammonia) and viability (insulin-stimulated (18)F-2-deoxyglucose). The primary endpoint was SCA defined as arrhythmic death or ICD discharge for ventricular fibrillation or ventricular tachycardia >240 beats/min.</AbstractText>After 4.1 years follow-up, cause-specific SCA was 16.2%. Infarct volume (22 ± 7% vs. 19 ± 9% of left ventricle [LV]) and LVEF (24 ± 8% vs. 28 ± 9%) were not predictors of SCA. In contrast, patients developing SCA had greater amounts of sympathetic denervation (33 ± 10% vs. 26 ± 11% of LV; p = 0.001) reflecting viable, denervated myocardium. The lower tertiles of sympathetic denervation had SCA rates of 1.2%/year and 2.2%/year, whereas the highest tertile had a rate of 6.7%/year. Multivariate predictors of SCA were PET sympathetic denervation, left ventricular end-diastolic volume index, creatinine, and no angiotensin inhibition. With optimized cut-points, the absence of all 4 risk factors identified low risk (44% of cohort; SCA <1%/year); whereas ≥2 factors identified high risk (20% of cohort; SCA ∼12%/year).</AbstractText>In ischemic cardiomyopathy, sympathetic denervation assessed using (11)C-HED PET predicts cause-specific mortality from SCA independently of LVEF and infarct volume. This may provide an improved approach for the identification of patients most likely to benefit from an ICD. (Prediction of ARrhythmic Events With Positron Emission Tomography [PAREPET]; NCT01400334).</AbstractText>Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,614 | A mutation in CALM1 encoding calmodulin in familial idiopathic ventricular fibrillation in childhood and adolescence. | This study aimed to identify the genetic defect in a family with idiopathic ventricular fibrillation (IVF) manifesting in childhood and adolescence.</AbstractText>Although sudden cardiac death in the young is rare, it frequently presents as the first clinical manifestation of an underlying inherited arrhythmia syndrome. Gene discovery for IVF is important as it enables the identification of individuals at risk, because except for arrhythmia, IVF does not manifest with identifiable clinical abnormalities.</AbstractText>Exome sequencing was carried out on 2 family members who were both successfully resuscitated from a cardiac arrest.</AbstractText>We characterized a family presenting with a history of ventricular fibrillation (VF) and sudden death without electrocardiographic or echocardiographic abnormalities at rest. Two siblings died suddenly at the ages of 9 and 10 years, and another 2 were resuscitated from out-of-hospital cardiac arrest with documented VF at ages 10 and 16 years, respectively. Exome sequencing identified a missense mutation affecting a highly conserved residue (p.F90L) in the CALM1 gene encoding calmodulin. This mutation was also carried by 1 of the siblings who died suddenly, from whom DNA was available. The mutation was present in the mother and in another sibling, both asymptomatic but displaying a marginally prolonged QT interval during exercise.</AbstractText>We identified a mutation in CALM1 underlying IVF manifesting in childhood and adolescence. The causality of the mutation is supported by previous studies demonstrating that F90 mediates the direct interaction of CaM with target peptides. Our approach highlights the utility of exome sequencing in uncovering the genetic defect even in families with a small number of affected individuals.</AbstractText>Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,615 | Multistage electrotherapy delivered through chronically-implanted leads terminates atrial fibrillation with lower energy than a single biphasic shock. | The goal of this study was to develop a low-energy, implantable device-based multistage electrotherapy (MSE) to terminate atrial fibrillation (AF).</AbstractText>Previous attempts to perform cardioversion of AF by using an implantable device were limited by the pain caused by use of a high-energy single biphasic shock (BPS).</AbstractText>Transvenous leads were implanted into the right atrium (RA), coronary sinus, and left pulmonary artery of 14 dogs. Self-sustaining AF was induced by 6 ± 2 weeks of high-rate RA pacing. Atrial defibrillation thresholds of standard versus experimental electrotherapies were measured in vivo and studied by using optical imaging in vitro.</AbstractText>The mean AF cycle length (CL) in vivo was 112 ± 21 ms (534 beats/min). The impedances of the RA-left pulmonary artery and RA-coronary sinus shock vectors were similar (121 ± 11 Ω vs. 126 ± 9 Ω; p = 0.27). BPS required 1.48 ± 0.91 J (165 ± 34 V) to terminate AF. In contrast, MSE terminated AF with significantly less energy (0.16 ± 0.16 J; p < 0.001) and significantly lower peak voltage (31.1 ± 19.3 V; p < 0.001). In vitro optical imaging studies found that AF was maintained by localized foci originating from pulmonary vein-left atrium interfaces. MSE Stage 1 shocks temporarily disrupted localized foci; MSE Stage 2 entrainment shocks continued to silence the localized foci driving AF; and MSE Stage 3 pacing stimuli enabled consistent RA-left atrium activation until sinus rhythm was restored.</AbstractText>Low-energy MSE significantly reduced the atrial defibrillation thresholds compared with BPS in a canine model of AF. MSE may enable painless, device-based AF therapy.</AbstractText>Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,616 | Association of the frontal QRS-T angle with adverse cardiac remodeling, impaired left and right ventricular function, and worse outcomes in heart failure with preserved ejection fraction. | No prior studies have investigated the association of QRS-T angle with cardiac structure and function and outcomes in heart failure with preserved ejection fraction (HFpEF). The aim of this study was to test the hypothesis that increased frontal QRS-T angle is associated with worse cardiac function and remodeling and adverse outcomes in HFpEF.</AbstractText>A total of 376 patients with HFpEF (i.e., symptomatic heart failure with left ventricular ejection fraction > 50%) were prospectively studied. The frontal QRS-T angle was calculated from the 12-lead electrocardiogram. Patients were divided into tertiles by frontal QRS-T angle (0°-26°, 27°-75°, and 76°-179°), and clinical, laboratory, and echocardiographic data were compared among groups. Cox proportional-hazards analyses were performed to determine the association between QRS-T angle and outcomes.</AbstractText>The mean age of the cohort was 64 ± 13 years, 65% were women, and the mean QRS-T angle was 61 ± 51°. Patients with increased QRS-T angles were older; had lower body mass indices; more frequently had coronary artery disease, diabetes, chronic kidney disease, and atrial fibrillation; and had higher B-type natriuretic peptide levels (P < .05 for all comparisons). After multivariate adjustment, patients with increased QRS-T angles had higher B-type natriuretic peptide levels in addition to higher left ventricular mass indices, worse diastolic function parameters, more right ventricular remodeling, and worse right ventricular systolic function (P < .05 for all associations). QRS-T angle was independently associated with the composite outcome of cardiovascular hospitalization or death on multivariate analysis, even after adjusting for B-type natriuretic peptide (heart rate for the highest QRS-T tertile, 2.0; 95% confidence interval, 1.2-3.4; P = .008).</AbstractText>In HFpEF, increased QRS-T angle is independently associated with worse left and right ventricular function and remodeling and adverse outcomes.</AbstractText>Copyright © 2014 American Society of Echocardiography. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
12,617 | The independent role of the aortic root ganglionated plexi in the initiation of atrial fibrillation: An experimental study. | The major atrial ganglionated plexi (GP) can initiate atrial fibrillation alone without any contribution from the extrinsic cardiac nervous system. However, if stimulation of the ventricular GP, especially the aortic root GP, can provoke atrial fibrillation (AF) alone is unknown. Our study was designed to investigate the independent role of aortic root GP activity in the initiation of AF.</AbstractText>In 10 Langendorff-perfused canine hearts, the atrial effective refractory period, pulmonary vein effective refractory period, and percentage of AF induced were measured at baseline and during aortic root GP stimulation.</AbstractText>Stimulation of the aortic root GP shortened the atrial effective refractory period from 128 ± 10 ms at baseline to 103 ± 15 ms (P < .05) and shortened the pulmonary vein effective refractory period from 139 ± 14 ms to 114 ± 15 ms (P < .05). Furthermore, the percentage of AF induced in the 10 isolated hearts increased from 10% at baseline to 90% during aortic root GP stimulation (P < .05).</AbstractText>In Langendorff-perfused canine hearts, stimulation of the aortic root GP provokes AF in the absence of any extrinsic cardiac nerve activity. The aortic root GP is an important element in the intrinsic neuronal loop that can increase the risk of AF in isolated heart models.</AbstractText>Copyright © 2014 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.</CopyrightInformation> |
12,618 | Lone atrial fibrillation in the pediatric population. | There are few reports of pediatric studies of atrial fibrillation (AF). We sought to describe the clinical characteristics, management strategies, and recurrence rates and to identify predictors of AF recurrence in a contemporary pediatric population.</AbstractText>A retrospective review was performed of patients ≤ 18 years with lone AF who were seen at 4 pediatric institutions from 1996-2011. Patients with AF in the setting of thyroid disease, ventricular pre-excitation, coexisting congenital heart disease, or a history of cardiac surgery were excluded. Demographics, clinical presentation, investigations, treatment, and follow-up were analyzed.</AbstractText>Forty-two patients were diagnosed with a first episode of lone AF, and 4 of these cases were later classified as persistent AF. Thirty-one (74%) were male patients, median age was 15.3 years, and median (interquartile range [IQR]) duration of AF episode was 12 (IQR, 7-24) hours. AF recurred in 39% (15 of 38) of patients. The Kaplan-Meier median time to estimated recurrence was 19 months. By univariate analysis, initial AF episode duration was associated with a higher risk of recurrence (hazard ratio [HR], 1.01; 95% confidence interval [CI], 1-1.02; P = 0.034). Sex, age, family history, size of the left atrium, and history of cardioversion were not associated with recurrence. Recurrence with another supraventricular tachyarrhythmia (SVT) was observed in 6 of 38 (16%) patients, and 12 patients underwent electrophysiology (EP) study, with 6 patients receiving ablation.</AbstractText>Our reported rate of recurrence of 39% is important when counseling pediatric patients and their parents on the expected course and treatment goals.</AbstractText>Copyright © 2013 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,619 | Effect of dronedarone on clinical end points in patients with atrial fibrillation and coronary heart disease: insights from the ATHENA trial. | This study aimed to assess safety and cardiovascular outcomes of dronedarone in patients with paroxysmal or persistent atrial fibrillation (AF) with coronary heart disease (CHD). Coronary heart disease is prevalent among AF patients and limits antiarrhythmic drug use because of their potentially life-threatening ventricular proarrhythmic effects.</AbstractText>This post hoc analysis evaluated 1405 patients with paroxysmal or persistent AF and CHD from the ATHENA trial. Follow-up lasted 2.5 years, during which patients received either dronedarone (400 mg twice daily) or a double-blind matching placebo. Primary outcome was time to first cardiovascular hospitalization or death due to any cause. Secondary end points included first hospitalization due to cardiovascular events. The primary outcome occurred in 350 of 737 (47%) placebo patients vs. 252 of 668 (38%) dronedarone patients [hazard ratio (HR) = 0.73; 95% confidence interval (CI) = 0.62-0.86; P = 0.0002] without a significant increase in number of adverse events. In addition, 42 of 668 patients receiving dronedarone suffered from a first acute coronary syndrome compared with 67 of 737 patients from the placebo group (HR = 0.67; 95% CI = 0.46-0.99; P = 0.04).</AbstractText>In this post hoc analysis, dronedarone on top of standard care in AF patients with CHD reduced cardiovascular hospitalization or death similar to that in the overall ATHENA population, and reduced a first acute coronary syndrome. Importantly, the safety profile in this subpopulation was also similar to that of the overall ATHENA population, with no excess in proarrhythmias. The mechanism of the cardiovascular protective effects is unclear and warrants further investigation.</AbstractText> |
12,620 | Class I antiarrhythmic drugs inhibit human cardiac two-pore-domain K(+) (K2 ₂p) channels. | Class IC antiarrhythmic drugs are commonly used for rhythm control in atrial fibrillation. In addition, class I drugs are administered to suppress ventricular tachyarrhythmia in selected cases. The multichannel blocking profile of class I compounds includes reduction of cardiac potassium currents in addition to their primary mechanism of action, sodium channel inhibition. Blockade of two-pore-domain potassium (K2P) channels in the heart causes action potential prolongation and may provide antiarrhythmic action in atrial fibrillation. This study was designed to elucidate inhibitory effects of class I antiarrhythmic drugs on K2P channels. Human K2P2.1 (TREK1) and hK2P3.1 (TASK1) channels were systematically tested for their sensitivity to clinically relevant class IA (ajmaline), class IB (mexiletine), and class IC (propafenone) antiarrhythmic compounds using whole-cell patch clamp and two-electrode voltage clamp electrophysiology in Chinese hamster ovary cells and in Xenopus oocytes. Mexiletine and propafenone inhibited hK2P2.1 (IC50,mexiletine=173µM; IC50,propafenone=7.6µM) and hK2P3.1 channels (IC50,mexiletine=97.3µM; IC50,propafenone=5.1µM) in mammalian cells. Ajmaline did not significantly reduce current amplitudes. K2P channels were blocked in open and closed states, resulting in resting membrane potential depolarization. Open rectification properties of the channels were not affected by class I drugs. In summary, class I antiarrhythmic drugs target cardiac K2P K(+) channels. Blockade of hK2P2.1 and hK2P3.1 potassium currents provides mechanistic evidence to establish cardiac K2P channels as antiarrhythmic drug targets. |
12,621 | Compound and digenic heterozygosity predicts lifetime arrhythmic outcome and sudden cardiac death in desmosomal gene-related arrhythmogenic right ventricular cardiomyopathy. | Mutations in genes encoding for desmosomal proteins are the most common cause of arrhythmogenic right ventricular cardiomyopathy (ARVC). We assessed the value of genotype for prediction of lifetime major arrhythmic events and sudden cardiac death (SCD) in desmosomal gene-related ARVC.</AbstractText>The overall study population included 134 desmosomal gene mutation carriers (68 men; median age 36 years [22-52]) from 44 consecutive ARVC families undergoing comprehensive genetic screening. The probability of experiencing a first major arrhythmic event or SCD during a lifetime was determined by using date of birth as start point for the time-to-event analysis, and was stratified by sex, desmosomal genes, mutation types, and genotype complexity (single versus multiple mutations). One hundred thirteen patients (84%) carried a single desmosomal gene mutation in desmoplakin (n=44; 39%), plakophilin-2 (n=38; 34%), desmoglein-2 (n=30; 26%), and desmocollin-2 (n=1; 1%), whereas 21 patients (16%) had a complex genotype with compound heterozygosity in 7 and digenic heterozygosity in 14. Over a median observation period of 39 (22-52) years, 22 patients (16%) from 20 different families had arrhythmic events, such as SCD (n=1), aborted SCD because of ventricular fibrillation (n=6), sustained ventricular tachycardia (n=14), and appropriate defibrillator intervention (n=1). Multiple desmosomal gene mutations and male sex were independent predictors of lifetime arrhythmic events with a hazard ratio of 3.71 (95% confidence interval, 1.54-8.92; P=0.003) and 2.76 (95% confidence interval, 1.19-6.41; P=0.02), respectively.</AbstractText>Compound/digenic heterozygosity was identified in 16% of ARVC-causing desmosomal gene mutation carriers and was a powerful risk factor for lifetime major arrhythmic events and SCD. These results support the use of comprehensive genetic screening of desmosomal genes for arrhythmic risk stratification in ARVC.</AbstractText> |
12,622 | A case of paroxysmal atrial fibrillation following low voltage electrocution. | Electrical injury may result in arrhythmias, however atrial fibrillation following low voltage electrocution is not a common occurrence.</AbstractText>A 70-year-old South-Asian woman with no prior history of cardiovascular disease presented following an accidental low voltage electrocution with loss of consciousness. On initial assessment she was found to be in atrial fibrillation with a moderate to rapid ventricular rate. Troponin I and 2D echo were normal. Transient rise in markers of muscle damage were noted. The arrhythmia resolved spontaneously without active intervention.</AbstractText>Loss of consciousness and the path of electrical conduction involving the heart may herald cardiac involvement following electrocution. Low voltage electrocution may cause cardiac insult. Conservative management may suffice in management of atrial fibrillation without cardiovascular compromise.</AbstractText> |
12,623 | Long-term follow-up of asymptomatic Brugada patients with inducible ventricular fibrillation under hydroquinidine. | To evaluate the long-term efficacy and safety of an electrophysiologically guided therapy, based on a strategy of treatment using hydroquinidine (HQ) among asymptomatic Brugada patients with inducible ventricular fibrillation (VF).</AbstractText>In two French reference centres, consecutive asymptomatic type 1 Brugada patients with inducible VF were treated with HQ (600 mg/day, targeting a therapeutic range between 3 and 6 µmol/L) and enroled in a specific follow-up (mean 6.6 ± 3 years), including a second programmed ventricular stimulation (PVS) under HQ. An implantable cardioverter defibrillator (ICD) was eventually implanted in patients inducible under HQ, or during follow-up in case of HQ intolerance, as well as occurrence of arrhythmic events. From a total of 397 Brugada patients, 44 were enroled (47 ± 10 years, 95% male). Of these, 34 (77%) were no more inducible (Group PVS-), and were maintained under HQ alone during a mean follow-up of 6.2 ± 3 years. In this group, an ICD was eventually implanted in four patients (12%), with occurrence of appropriate ICD therapies in one. Among the 10 other patients (22%), who remained inducible and received ICD (Group PVS+), none of them received appropriate therapy during a mean follow-up of 7.7 ± 2 years. The overall annual rate of arrhythmic events was 1.04% (95% confidence interval 0.00-2.21), without any significant difference according to the result of PVS under HQ. One-third of patients experienced device-related complications.</AbstractText>Our long-term follow-up results emphasize that the rate of arrhythmic events among asymptomatic Brugada patients with inducible VF remains low over time. Our results also suggest that residual inducibility under HQ is of limited value to predict events during follow-up.</AbstractText> |
12,624 | Epidemiology of arrhythmias and sudden cardiac death in Asia. | Cardiac arrhythmias are cardiac rhythm disorders that comprise an important epidemiological and public health problem. Cardiac arrhythmias are significantly associated with increased risks of cardiovascular complications and sudden death, consequently leading to decreased quality of life, disability, high mortality, and healthcare expense. Atrial fibrillation (AF) is the most common sustained arrhythmia, and has been further increasing with the aging of society. Although the prevalence is relatively lower in Asians than in Westerners, the prognostic impacts on stroke and mortality in Asians are comparable. Sudden cardiac death (SCD) occurs in approximately 40 cases per 100,000 persons annually in each country of Asia. Most cases are caused by myocardial infarction and ventricular fibrillation in out-of-hospital cardiac arrest cases, but the proportion of myocardial infarction is lower in Asia than in Western countries. The primary electrophysiological disorders related to channelopathies, such as long QT syndrome, short QT syndrome, Brugada syndrome, early repolarization syndrome, and catecholaminergic polymorphic ventricular tachycardia, are estimated to be responsible for 10% of SCDs. Implantable cardioverter-defibrillator implantation has become established as an effective secondary prevention for SCD, and numbers have been increasing annually worldwide. New insights into arrhythmic diseases have been emerging from epidemiological, clinical, and genetic research, and contribute to improvements in diagnosis and prognosis.  |
12,625 | Primary Angioplasty for Cardiac Allograft Vasculopathy Presenting as ST-Elevation Acute Myocardial Infarction during Endomyocardial Biopsy. | Cardiac allograft vasculopathy is still a major issue, with significative mortality in heart transplant patients, and the best therapeutic options are not yet established. The progressively higher survival rates after transplantation have made it a major concern. This is a case report about a patient who underwent cardiac transplantation due to chagasic cardiomiopathy. During an endomyocardial biopsy more than 2 years after the transplant, the patient arrested in ventricular fibrillation, with ST-elevation in anterior leads after defibrillation. The angiography showed total occlusion of proximal left anterior descending artery, promptly treated with primary angioplasty, with excellent angiographic and clinical results. |
12,626 | Atrium-specific Kir3.x determines inducibility, dynamics, and termination of fibrillation by regulating restitution-driven alternans. | Atrial fibrillation is the most common cardiac arrhythmia. Ventricular proarrhythmia hinders pharmacological atrial fibrillation treatment. Modulation of atrium-specific Kir3.x channels, which generate a constitutively active current (I(K,ACh-c)) after atrial remodeling, might circumvent this problem. However, it is unknown whether and how I(K,ACh-c) contributes to atrial fibrillation induction, dynamics, and termination. Therefore, we investigated the effects of I(K,ACh-c) blockade and Kir3.x downregulation on atrial fibrillation.</AbstractText>Neonatal rat atrial cardiomyocyte cultures and intact atria were burst paced to induce reentry. To study the effects of Kir3.x on action potential characteristics and propagation patterns, cultures were treated with tertiapin or transduced with lentiviral vectors encoding Kcnj3- or Kcnj5-specific shRNAs. Kir3.1 and Kir3.4 were expressed in atrial but not in ventricular cardiomyocyte cultures. Tertiapin prolonged action potential duration (APD; 54.7±24.0 to 128.8±16.9 milliseconds; P<0.0001) in atrial cultures during reentry, indicating the presence of I(K,ACh-c). Furthermore, tertiapin decreased rotor frequency (14.4±7.4 to 6.6±2.0 Hz; P<0.05) and complexity (6.6±7.7 to 0.6±0.8 phase singularities; P<0.0001). Knockdown of Kcnj3 or Kcnj5 gave similar results. Blockade of I(K,ACh-c) prevented/terminated reentry by prolonging APD and changing APD and conduction velocity restitution slopes, thereby altering the probability of APD alternans and rotor destabilization. Whole-heart mapping experiments confirmed key findings (e.g., >50% reduction in atrial fibrillation inducibility after I(K,ACh-c) blockade).</AbstractText>Atrium-specific Kir3.x controls the induction, dynamics, and termination of fibrillation by modulating APD and APD/conduction velocity restitution slopes in atrial tissue with I(K,ACh-c). This study provides new molecular and mechanistic insights into atrial tachyarrhythmias and identifies Kir3.x as a promising atrium-specific target for antiarrhythmic strategies.</AbstractText> |
12,627 | Prognostic impact of early ventricular fibrillation in patients with ST-elevation myocardial infarction treated with primary PCI. | Current guidelines do not advocate implantation of cardioverter-defibrillators (ICD) for survivors of ventricular fibrillation (VF) during the first 48 hours of ST-elevation myocardial infarction (STEMI). However, contemporary studies in a real-life setting with long-term follow-up are lacking. We assessed the prognostic impact of early VF in a non-selected population of STEMI patients treated with primary percutaneous coronary intervention (PCI).</AbstractText>Consecutive STEMI patients admitted to a Swedish tertiary care hospital during 2007-2009 were identified from the Register of Information and Knowledge about Swedish Heart Intensive Care Admissions (n=1718, age 66±12 years, 70% male). Patients with VF were identified from the register, and medical records were reviewed to determine the time point of VF. Patients surviving VF in the first 48 hours after symptom onset were compared with patients without VF for one-year mortality and a combined endpoint of death, resuscitated VF or appropriate ICD therapy. VF within 48 hours occurred in 7% of STEMI patients (n=121). In patients alive at 48 hours (n=1663), VF patients (n=101) had higher in-hospital mortality (12% vs. 2%, p<0.001). However, in VF patients discharged alive (n=89), mortality was low (1%) and combined endpoint rate (3%) did not differ compared with patients without VF (n=1538; 4% and 4% respectively).</AbstractText>In a large non-selected population of STEMI patients treated with primary PCI, VF during the first 48 hours after STEMI is associated with increased in-hospital mortality but does not influence the long-term prognosis for those discharged alive.</AbstractText> |
12,628 | Synchronized defibrillation for ventricular fibrillation. | Optimization of defibrillation success is important to improve efficacy and minimize post-shock sequelae. Previous work has suggested an improvement in shock success when an intracardiac shock is delivered synchronized to the upslope of a VF wave. We investigated the efficacy of transthoracic defibrillation success using a novel external biphasic defibrillator which delivers shocks synchronized to the upslope of the surface ECG.</AbstractText>A prospective, controlled, randomized study in a research institute laboratory of male and female pigs (54.2±1.8 kg). Ventricular fibrillation (VF) was induced in 10 anaesthetized and ventilated pigs. Shocks were delivered randomly from a biphasic defibrillator in synchronized or non-synchronized mode via self-adhesive electrode pads following 30 s of VF. Energy settings at 50, 70, 80, and 100J were randomly tested. VF amplitude, impedance, and shock outcome were recorded and analysed digitally.</AbstractText>A total of 300 shocks were delivered. Synchronized shocks were delivered on the upslope of the VF wave in 99% of cases. There was no significant difference in shock success between shocks delivered in synchronized or non-synchronized modes (p=0.695). There was no significant difference in the amplitude of VF between successful and unsuccessful shocks (p=0.163). Furthermore, there was no association between shock success and transthoracic impedance.</AbstractText>The novel defibrillator used in this study was able to consistently deliver shocks on the upslope portion of the VF wave but did not show an improvement in shock success.</AbstractText> |
12,629 | QRS fragmentation in patients with arrhythmogenic right ventricular cardiomyopathy and complete right bundle branch block: a risk stratification. | Patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) and complete right bundle branch block (RBBB) very often have recurrent ventricular tachycardia and develop biventricular heart failure in the follow up, requiring heart transplantation and/or diuretics. In other patients with ARVC/D excluding RBBB, QRS fragmentation in the S wave of right precordial leads identifies patients with recurrent ventricular tachycardia, primary ventricular fibrillation, and recurrent implantable cardioverter defibrillator discharges; QRS fragmentation ≥3 leads characterized patients who died from sudden cardiac death.</AbstractText>In a cohort of 374 patients with ARVC/D (208 males; mean±SD age 46.5±14.8 years), there were 22 patients with complete RBBB: 17 patients with ARVD/C developed complete RBBB and had biventricular heart failure in a follow up of 4-6 years. In five patients with ARVC/D, complete RBBB was initially evident. In all patients with ARVC/D and RBBB, QRS fragmentation ≥3 of all 12 ECG leads and QRS fragmentation in the S wave of right precordial leads were analysed.</AbstractText>QRS fragmentation ≥3 of all 12 ECG leads and in the S wave of right precordial leads were present in 16/17 patients who developed RBBB and none of the five patients with initial RBBB. In one patient with initial RBBB, QRS fragmentation ≥3 leads was present (r=17.45; p<0.0001).</AbstractText>Patients with recurrent ventricular tachycardia who develop biventricular heart failure requiring heart transplantation and/or diuretics are characterized by QRS fragmentation in the S wave of right precordial leads and ≥3 of all 12 ECG leads. These results are statistically significant. Patients with initial RBBB have an overall benign prognosis.</AbstractText> |
12,630 | The investigation of sudden arrhythmic death syndrome (SADS)-the current approach to family screening and the future role of genomics and stem cell technology. | SADS is defined as sudden death under the age of 40 years old in the absence of structural heart disease. Family screening studies are able to identify a cause in up to 50% of cases-most commonly long QT syndrome (LQTS), Brugada and early repolarization syndrome, and catecholaminergic polymorphic ventricular tachycardia (CPVT) using standard clinical screening investigations including pharmacological challenge testing. These diagnoses may be supported by genetic testing which can aid cascade screening and may help guide management. In the current era it is possible to undertake molecular autopsy provided suitable samples of DNA can be obtained from the proband. With the evolution of rapid sequencing techniques it is possible to sequence the whole exome for candidate genes. This major advance offers the opportunity to identify novel causes of lethal arrhythmia but also poses the challenge of managing the volume of data generated and evaluating variants of unknown significance (VUS). The emergence of induced pluripotent stem cell technology could enable evaluation of the electrophysiological relevance of specific ion channel mutations in the proband or their relatives and will potentially enable screening of idiopathic ventricular fibrillation survivors combining genetic and electrophysiological studies in derived myocytes. This also could facilitate the assessment of personalized preventative pharmacological therapies. This review will evaluate the current screening strategies in SADS families, the role of molecular autopsy and genetic testing and the potential applications of molecular and cellular diagnostic strategies on the horizon. |
12,631 | The Connexin40A96S mutation from a patient with atrial fibrillation causes decreased atrial conduction velocities and sustained episodes of induced atrial fibrillation in mice. | Atrial fibrillation (AF) is the most common type of cardiac arrhythmia and a major cause of stroke. In the mammalian heart the gap junction proteins connexin40 (Cx40) and connexin43 (Cx43) are strongly expressed in the atrial myocardium mediating effective propagation of electrical impulses. Different heterozygous mutations in the coding region for Cx40 were identified in patients with AF. We have generated transgenic Cx40A96S mice harboring one of these mutations, the loss-of-function Cx40A96S mutation, as a model for atrial fibrillation. Cx40A96S mice were characterized by immunochemical and electrophysiological analyses. Significantly reduced atrial conduction velocities and strongly prolonged episodes of atrial fibrillation were found after induction in Cx40A96S mice. Analyses of the gating properties of Cx40A96S channels in cultured HeLa cells also revealed significantly lower junctional conductance and enhanced sensitivity voltage gating of Cx40A96S in comparison to Cx40 wild-type gap junctions. This is caused by reduced open probabilities of Cx40A96S gap junction channels, while single channel conductance remained the same. Similar to the corresponding patient, heterozygous Cx40A96S mice revealed normal expression levels and localization of the Cx40 protein. We conclude that heterozygous Cx40A96S mice exhibit prolonged episodes of induced atrial fibrillation and severely reduced atrial conduction velocities similar to the corresponding human patient. |
12,632 | Added value of cardiac magnetic resonance in etiological diagnosis of ventricular arrhythmias. | Cardiac magnetic resonance (CMR) imaging is increasingly important in the diagnostic work-up of a wide range of heart diseases, including those with arrhythmogenic potential.</AbstractText>To assess the added value of CMR in etiological diagnosis of ventricular arrhythmias after an inconclusive conventional investigation.</AbstractText>Patients undergoing CMR between 2005 and 2011 for investigation of ventricular arrhythmias were included (n=113). All had documented arrhythmias. Those with a definite diagnosis from a previous investigation and those with evidence of coronary artery disease (acute coronary syndrome, typical angina symptoms, increase in biomarkers or positive stress test) were excluded. CMR results were considered relevant when they fulfilled diagnostic criteria.</AbstractText>Of the 113 patients, 57.5% were male and mean age was 41.7 ± 16.2 years. Regarding the initial arrhythmia, 38.1% had ventricular fibrillation/sustained ventricular tachycardia (VF/VT) and 61.9% had less complex ventricular ectopy. CMR imaging showed criteria of a specific diagnosis in 42.5% of patients, was totally normal in 36.3%, and showed non-specific alterations in the remainder. In VF/VT patients, specific criteria were found in 60.4%, and in 31.4% of those with less complex ectopy. The most frequent diagnoses were arrhythmogenic right ventricular dysplasia, ventricular non-compaction and myopericarditis. It is worth noting that, although there was no evidence of previous coronary artery disease, 6.2% of patients had a late gadolinium enhancement distribution pattern compatible with myocardial infarction.</AbstractText>CMR gives additional and important information in the diagnostic work-up of ventricular arrhythmias after an inconclusive initial investigation. The proportion of patients with diagnostic criteria was 42.5% (60.0% in those with VF/VT), and CMR was completely normal in 36.6%.</AbstractText>Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.</CopyrightInformation> |
12,633 | Enhanced external counterpulsation improves cerebral blood flow following cardiopulmonary resuscitation. | To investigate the therapeutic value of enhanced external counterpulsation (EECP) on recovery of cerebral blood flow following cardiac arrest (CA) and successful resumption of spontaneous circulation (ROSC) by cardiopulmonary resuscitation.</AbstractText>CA models were conducted using beagle dogs induced by alternating current. After successful ROSC by cardiopulmonary resuscitation, 16 dogs were randomly divided into the EECP and control group (n = 8 per group). Dogs underwent dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging at baseline prior to CA and during the 3 days following ROSC. Mean blood pressure, right common carotid artery blood flow, intracranial microcirculation and blood lactate levels were measured. Neurological outcome was assessed by the neurologic deficit score. Hematoxylin-eosin staining and transmission electron microscopy were performed for morphology and microconstruction of the cerebral cortex.</AbstractText>The EECP group exhibited a significant elevation in right common carotid artery blood flow, intracranial microcirculation and a substantial decrease in blood lactate levels relative to the control group. Relative cerebral blood flow and volume were higher in the EECP group during the 3 days. Apparent diffusion coefficients were significantly higher in the EECP group on the first and third days. After ROSC, the neurologic deficit score was significantly higher in the control group compared to those in the EECP group during the three days of experiment. The cell swelling of neurons and increase of mitochondrial mass were more pronounced in the control group.</AbstractText>EECP is beneficial for recovery of cerebral blood flow and attenuation of ischemic cerebral edema following CA and successful ROSC.</AbstractText>© 2013.</CopyrightInformation> |
12,634 | Hemodynamic rescue and ECG stability during chest compressions using adenosine and lidocaine after 8-minute asphyxial hypoxia in the rat. | Sudden cardiac death generally arises from either ventricular fibrillation or asphyxial hypoxia. In an effort to translate the cardioprotective effects of adenosine and lidocaine (AL) from hemorrhagic shock to cardiopulmonary resuscitation, we examined the effect of AL on hemodynamics and electrocardiogram (ECG) stability in the rat model of asphyxial hypoxia.</AbstractText>Male Sprague-Dawley rats were randomly assigned to 1 of 4 groups (n = 8): saline (SAL), adenosine (ADO), lidocaine (LIDO), and AL. Cardiac arrest (mean arterial pressure <10 mm Hg) was induced by clamping the ventilator line for 8 minutes. A 0.5-mL intravenous drug bolus was injected followed by chest compressions (300 min(-1)), which were repeated every 5 minutes for 1 hour.</AbstractText>Return of spontaneous circulation was achieved in 5 SAL (62.6%), 4 ADO (50%), 7 LIDO (87.5%), and 8 AL rats (100%) within 5 minutes but could not be sustained. During chest compressions, mean arterial pressure was consistently higher in the AL-treated rats compared with all groups (P < .05; 35-45 and 55 minutes) followed by the LIDO group and was lowest in the ADO and SAL groups (P < .05). Systolic pressure followed a similar pattern. In addition, diastolic pressure in the AL-treated rats was significantly higher from 25 to 60 minutes than LIDO and ADO alone or SAL, and heart rate was 30% to 40% lower. Improved ECG rhythm and R-R variability were apparent in AL-treated rats during early compressions and hands-off intervals.</AbstractText>We conclude that a small bolus of 0.9% NaCl AL improved hemodynamics with possible diastolic rescue and ECG stabilization during chest compressions compared with ADO, LIDO, or SAL controls.</AbstractText>Copyright © 2013 Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,635 | Congenital long QT syndrome with compound mutations in the KCNH2 gene. | Congenital long QT syndrome is a genetic disorder encompassing a family of mutations that can lead to aberrant ventricular electrical activity. We report on two brothers with long QT syndrome caused by compound mutations in the KCNH2 gene inherited from parents who had no prolonged QT interval on electrocardiography. The proband had syncope, and his elder brother suffered from ventricular fibrillation. Genetic testing revealed that both brothers had multiple mutations in the KCNH2 gene, including a missense mutation of C1474T (exon 6) as well as a frameshift/nonsense mutation, resulting from the insertion of 25 nucleotides, which caused an altered amino acid sequence beginning at codon 302 and a premature termination codon (i.e., TAG) at codon 339 (exon 4). Family genetic screening found that their father had the same frameshift mutation, and their mother and sister had the same missense mutation, in the KCNH2 gene. However, these other family members were asymptomatic, with normal QT intervals on electrocardiography. These results suggest that compound mutations in the KCNH2 gene inherited independently from the parents made the phenotypes of their sons more severe. |
12,636 | Life-threatening ventricular arrhythmias during ajmaline challenge in patients with Brugada syndrome: incidence, clinical features, and prognosis. | Sustained ventricular arrhythmias (sVAs), such as polymorphic ventricular tachycardia or ventricular fibrillation, can complicate ajmaline challenge in patients with Brugada syndrome (BS).</AbstractText>To assess the incidence of life-threatening sVAs during ajmaline administration in a large series of patients with BS. In addition, clinical characteristics as well as prognosis of these patients were evaluated.</AbstractText>All consecutive patients with ajmaline-induced diagnosis of BS were eligible for this study.</AbstractText>A total of 503 patients were included. Nine (1.8%) patients (44% men; mean age 26 ± 18 years) developed a life-threatening sVA during ajmaline challenge. Three patients (33%)were children, and 2 (22%) patients experienced sVAs refractory to the first external defibrillation. One patient underwent venoarterial extracorporeal membrane oxygenation to restore sinus rhythm. Age at the time of ajmaline challenge was significantly lower in patients with sVAs compared with patients without sVAs (26 ± 18 years vs 41 ± 18 years; P = .01). Moreover, patients with sVAs presented more frequently with sinus node dysfunction compared with patients with normal response to ajmaline (22.2% vs 1.4%; P = .01). After a mean follow-up time of 29 ± 8 months, none of the patients who had developed a sVA during ajmaline challenge died suddenly or developed further life-threatening ventricular arrhythmias.</AbstractText>sVA during ajmaline challenge is not a rare event in BS occurring in 9 (1.8%) patients. Despite its challenging acute treatment, the occurrence of ajmaline-induced sVAs in patients with BS might not identify a category at higher risk for further arrhythmic events.</AbstractText>© 2013 Heart Rhythm Society Published by Heart Rhythm Society All rights reserved.</CopyrightInformation> |
12,637 | Therapeutic hypothermia following cardiac arrest. | More than 10 years ago, the randomised studies of therapeutic hypothermia after cardiac arrest showed significant improvement of neurological outcome and survival. Since then, it has become clear that most of the possible adverse events of therapeutic hypothermia are mild and can easily be controlled by proper administration of intensive care. Although implementation of this effective therapy is quite successful, many questions of the exact treatment protocol still remain unanswered. Therapeutic hypothermia treatment therefore must be tailored to the specific patient's needs. Hence, the exact level of target temperature, duration of cooling, rewarming, timing of the therapy and concomitant medication to facilitate therapeutic hypothermia will be important in the future. Additionally, the use of a post-resuscitation treatment bundle (specialised cardiac-arrest centres including intensive post-resuscitation care, appropriate haemodynamic and respiratory management, therapeutic hypothermia and percutaneous coronary intervention) could further improve treatment of cardiac arrest. |
12,638 | Catheter ablation of atrial fibrillation in heart failure. | Atrial fibrillation in the presence of heart failure is an independent predictor of mortality and is associated with increased hospitalizations and worsening New York Heart Association functional class. Despite these associations, large-scale trials have not shown a benefit in rhythm restoration. However, further analysis of these trials showed that patients who remained in sinus rhythm did have improved survival rates. Studies to examine the efficacy of catheter ablation of atrial fibrillation were therefore conducted and reported efficacy rates ranging from 50% to 92% at maintaining sinus rhythm with associated improvements in left ventricular ejection fraction, quality of life, and New York Heart Association functional class. |
12,639 | The role of ablation of the atrioventricular junction in patients with heart failure and atrial fibrillation. | Ablation of the atrioventricular junction (AVJ) is a technically easy procedure that is safe and has a high success rate as an intervention for effective ventricular rate control in patients in symptomatic atrial fibrillation. AVJ ablation has been reported to improve quality of life, left ventricular ejection fraction, and exercise duration in these patients and minimize the incidence of inappropriate shocks. Because right ventricular pacing after AVJ ablation may result in decrease in left ventricular function and worsening of heart failure symptoms, there is increasing evidence to support the effectiveness of cardiac resynchronization therapy in atrial fibrillation populations. |
12,640 | Ventricular rate control of atrial fibrillation in heart failure. | In the last few years, there has been a major shift in the treatment of atrial fibrillation (AF) in the setting of hear failure (HF), from rhythm to ventricular rate control in most patients with both conditions. In this article, the authors focus on ventricular rate control and discuss the indications; the optimal ventricular rate-control target, including detailed results of the Rate Control Efficacy in Permanent Atrial Fibrillation: a Comparison Between Lenient versus Strict Rate Control II (RACE II) study; and the pharmacologic and nonpharmacologic options to control the ventricular rate during AF in the setting of HF. |
12,641 | Aortic valve stenosis and atrial fibrillation influence plasma fibulin-1 levels in patients treated with coronary bypass surgery. | Aortic valve stenosis (AS) causes cardiac fibrosis and left ventricular hypertrophy, and over time heart failure can occur. To date, a reliable marker to predict progression of AS or the development of heart failure is still lacking. In this study, we addressed the hypothesis that fibulin-1 levels reflect myocardial fibrosis.</AbstractText>Patients undergoing heart surgery at the Odense University were investigated. By 2012 data on outcome were obtained.</AbstractText>In 293 patients, plasma fibulin-1 levels were measured. Patients with AS or atrial fibrillation (AF) had significantly higher fibulin-1 levels compared to those with coronary artery disease only (p = 0.005). Patients with preoperatively diagnosed chronic AF had significantly higher levels of fibulin-1 compared to those without (p = 0.004). Plasma fibulin-1 levels showed no relationship to echocardiographic size and had no impact on outcome, death or other adverse events.</AbstractText>This study shows that plasma fibulin-1 levels are increased in patients with AS and AF compared to patients with coronary disease only. Our study results suggest fibulin-1, a vascular extracellular matrix (ECM) protein, as a marker of ECM turnover perhaps due to the increased myocardial stretch that is related to pressure overload.</AbstractText>Copyright © 2013 S. Karger AG, Basel.</CopyrightInformation> |
12,642 | Function and regulation of serine/threonine phosphatases in the healthy and diseased heart. | Protein phosphorylation is a major control mechanism of a wide range of physiological processes and plays an important role in cardiac pathophysiology. Serine/threonine protein phosphatases control the dephosphorylation of a variety of cardiac proteins, thereby fine-tuning cardiac electrophysiology and function. Specificity of protein phosphatases type-1 and type-2A is achieved by multiprotein complexes that target the catalytic subunits to specific subcellular domains. Here, we describe the composition, regulation and target substrates of serine/threonine phosphatases in the heart. In addition, we provide an overview of pharmacological tools and genetic models to study the role of cardiac phosphatases. Finally, we review the role of protein phosphatases in the diseased heart, particularly in ventricular arrhythmias and atrial fibrillation and discuss their role as potential therapeutic targets. |
12,643 | Symptomatic pulmonary hypertension with giant left atrial v waves after surgical maze procedures: evaluation by comprehensive hemodynamic catheterization. | The surgical maze procedure is highly effective in treating symptomatic atrial fibrillation but may have detrimental effects on left atrial (LA) contractile function and compliance.</AbstractText>To describe a series of patients presenting with symptomatic pulmonary hypertension due in part to LA dysfunction after surgical maze procedures.</AbstractText>This report includes 9 patients who (1) presented to Mayo Clinic (Rochester, MN) between 2008 and 2012 with unexplained dyspnea and pulmonary hypertension after the surgical maze procedure, (2) underwent comprehensive hemodynamic catheterization with transseptal measurement of LA pressure, (3) had large v waves on LA pressure waveforms, and (4) did not have significant mitral valve regurgitation or stenosis or pulmonary vein stenosis.</AbstractText>Invasive hemodynamic assessment revealed (1) severe pulmonary hypertension (mean pulmonary pressure 47 ± 6 mm Hg), (2) severe LA hypertension (27 ± 4 mm Hg), (3) giant LA v waves (to 50 ± 8 mm Hg), (4) absence of LA or left ventricular a waves, and (5) blunted x descents (2 ± 1 mm Hg). Left ventricular end-diastolic pressure was also elevated (20 ± 5 mm Hg).</AbstractText>Abnormalities in LA compliance and contractility may lead to giant LA v waves and symptomatic pulmonary hypertension after surgical maze procedures. This syndrome should be considered in the differential diagnosis for pulmonary hypertension and underscores the importance of comprehensive hemodynamic catheterization.</AbstractText>© 2013 Heart Rhythm Society Published by Heart Rhythm Society All rights reserved.</CopyrightInformation> |
12,644 | Evidence for cardiac safety and antiarrhythmic potential of chloroquine in systemic lupus erythematosus. | To perform a comprehensive evaluation of heart rhythm disorders and the influence of disease/therapy factors in a large systemic lupus erythematosus (SLE) cohort.</AbstractText>Three hundred and seventeen consecutive patients of an ongoing electronic database protocol were evaluated by resting electrocardiogram and 142 were randomly selected for 24 h Holter monitoring for arrhythmia and conduction disturbances. The mean age was 40.2 ± 12.1 years and disease duration was 11.4 ± 8.1 years. Chloroquine (CQ) therapy was identified in 69.7% with a mean use of 8.5 ± 6.7 years. Electrocardiogram abnormalities were detected in 66 patients (20.8%): prolonged QTc/QTd (14.2%); bundle-branch block (2.5%); and atrioventricular block (AVB) (1.6%). Age was associated with AVB (P = 0.029) and prolonged QTc/QTd (P = 0.039) whereas anti-Ro/SS-A and Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores were not (P > 0.05). Chloroquine was negatively associated with AVB (P = 0.01) as was its longer use (6.1 ± 6.9 vs. 1.0 ± 2.5 years, P = 0.018). Time of CQ use was related with the absence of AVB [odds ratio (OR) = 0.103; 95% confidence interval (CI) = 0.011-0.934, P = 0.043] in multiple logistic regression. Holter monitoring revealed abnormalities in 121 patients (85.2%): supraventricular ectopies (63.4%) and tachyarrhythmia (18.3%); ventricular ectopies (45.8%). Atrial tachycardia/fibrillation (AT/AF) were associated with shorter CQ duration (7.05 ± 7.99 vs. 3.63 ± 5.02 years, P = 0.043) with a trend to less CQ use (P = 0.054), and older age (P < 0.001). Predictors of AT/AF in multiple logistic regression were age (OR = 1.115; 95% CI = 1.059-1.174, P < 0.001) and anti-Ro/SS-A (OR = 0.172; 95% CI = 0.047-0.629, P = 0.008).</AbstractText>Chloroquine seems to play a protective role in the unexpected high rate of cardiac arrhythmias and conduction disturbances observed in SLE. Further studies are necessary to determine if this antiarrhythmic effect is due to the disease control or a direct effect of the drug.</AbstractText>Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2013. For permissions please email: journals.permissions@oup.com.</CopyrightInformation> |
12,645 | Effect of levosimendan on survival and adverse events after cardiac surgery: a meta-analysis. | Left ventricular systolic dysfunction is associated with increased morbidity and mortality in patients undergoing cardiac surgery. The authors performed a meta-analysis investigating the effects of levosimendan in cardiac surgery patients with and without preoperative systolic dysfunction.</AbstractText>Meta-analysis of randomized controlled trials.</AbstractText>Hospital.</AbstractText>The 1,155 patients who participated in 14 randomized controlled trials of perioperative levosimendan were included.</AbstractText>None.</AbstractText>PubMed, EMBASE, the Cochrane database of clinical trials, and conference proceedings were searched for clinical trials of perioperative levosimendan in patients undergoing cardiac surgery through May 1, 2012. Studies were grouped by mean ejection fraction (EF). Those with a mean EF <40% were designated as low-EF. Pooled results demonstrated a reduction in mortality with levosimendan (risk difference [RD]-4.2%; 95% CI -7.2%, -1.1%; p = 0.008). Subgroup analysis showed that this benefit was confined to the low-EF studies (RD -7.0%; 95% CI -11.0%, -3.1%; p < 0.001). No benefit was observed in the preserved-EF subgroup (RD +1.1%; 95% CI -3.8%, +5.9%; p = 0.66). Significant reductions also were seen in the need for dialysis (RD -4.9%; 95% CI -8.2%, -1.6%; p = 0.003), myocardial injury (RD -5.0%; 95% CI -8.3%, -1.7%; p = 0.003), and postoperative atrial fibrillation (RD -8.1%; 95% CI -13.3%, -3.0%; p = 0.002).</AbstractText>Levosimendan was associated with reduced mortality and other adverse outcomes in patients undergoing cardiac surgery, and these benefits were greatest in patients with reduced EF. These data support the need for adequately powered randomized clinical trials to confirm the benefits of levosimendan in patients with reduced EF undergoing cardiac surgery.</AbstractText>Copyright © 2013 Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,646 | [Atypical form of tako-tsubo cardiomyopathy in a patient with atrial fibrillation in Wolff-Parkinson-White syndrome complicated with ventricular fibrillation: the diagnostic problems]. | Atypical form of tako-tsubo cardiomyopathy (TTC) is associated with regional wall motion abnormalities in basal and/or middle segments or only middle segments with sparing of apical segments or apical and basal segments. We described a case of47-year-old female with atypical form of TTC due to fast atrial fibrillation that converted into ventricular fibrillation in WPW syndrome. The echocardiogram made after direct current cardioversion revealed decreased left ventricular ejection fraction (LVEF 35%) with akinesis of inferior and posterior walls and anterior part of interventricular septum in the middle and the basal segments with hyperkinesis of apical segments. The biochemistry blood samples revealed elevated both troponin T- 0.35 ng/mL and NT-proBNP - 3550 pg/mL plasma level. The ECG showed sinus rhythm 62 bpm, shortened PQ interval 100 ms, widened QRS duration - 115 ms with delta wave, prolonged QT interval - 520 ms, QS in leads: II, III, aVF. NegativeT waves in leads: I, aVL and positive, symmetrical T waves in leads V1-V6. The coronarography revealed normal coronaryarteries. The control echocardiography after 10 days showed normal LVEF 70%, without any wall motion abnormalities. TTC was recognised based on: history of sudden stress situation before, ischaemic ECG changes, positive markers of myocardial injury, transient segmental wall motion abnormalities and normal coronary arteries. The ablation of right postero-septal accessory pathway was successfully performed. |
12,647 | Catheter ablation of complex left atrial arrhythmias in patients after percutaneous or surgical mitral valve procedures. | Mitral valve defects are frequently associated with atrial arrhythmias. Percutaneous or surgical mitral valveprocedures may reverse adverse haemodynamic consequences of the valvular defect but have little effect on the arrhythmiaitself. With safety concerns and few outcome data, the role of catheter ablation in these patients has not been established yet.</AbstractText>To assess safety and efficacy of catheter ablation of complex left atrial arrhythmias in patients after percutaneous orsurgical mitral valve procedures.</AbstractText>We studied 14 patients (mean age 55 ± 11 years; 9 females) with a history of percutaneous mitral commissurotomy (PMC; n = 5), surgical valvuloplasty (n = 3), or mitral valve replacement (n = 6) due to mitral stenosis (MS; n = 8) or mitral regurgitation (MR; n = 6). In surgically treated patients, concomitant pulmonary vein isolation was performed in 6 patients and tricuspid valvuloplasty in 4 patients. Atrial fibrillation (AF) was the only arrhythmia in 7 patients, including all 5 patients after PMC (paroxysmal AF in 2 patients, persistent AF in 4 patients, long-persistent AF in 1 patient). Left atrial tachycardia (AT) was the prevailing arrhythmia in 7 of 9 patients after surgical procedures (median of 2 morphologies per patient), lasting uninterrupted for 1 to 48 months before the ablation procedure. The ablation scheme was adjusted to the clinical and electrophysiological status and included pulmonary vein isolation, linear lesions and ablation of fragmented potentials. Atrial tachycardias were mapped and ablated using activation and entrainment mapping.</AbstractText>Efficacy of ablation after a single procedure was 36%. A total of 25 ablations were ultimately performed in the study group. During 23 ± 13 months of follow-up, stable sinus rhythm (SR) was present in 10 (71.4%) patients, including 4 on antiarrhythmic drugs. No differences in the efficacy of ablation were seen between patients with MS and MR, with SR obtained in5 of 8 patients and 5 of 6 patients, respectively (p = 0.57). Similarly, no differences in regard to SR maintenance were noted between patients previously treated by a percutaneous or surgical procedure (percutaneous treatment: SR in 3 of 5 patients; surgical treatment: SR in 7 of 9 patients, p = 0.58). SR was obtained in 5 of 7 patients in whom the original arrhythmia was AF and in 5 of 7 patients who had AT (p = 1.00). Patients in whom stable SR was obtained showed a significantly better functional status as assessed by the New York Heart Association classification, accompanied by a reduction of the left atrial dimension and an increase in the left ventricular ejection fraction.</AbstractText>Catheter ablation of complex left atrial arrhythmias in patients after percutaneous or surgical mitral valve proceduresis an effective and safe therapeutic option. Recurrences after the first ablation are frequent and patients may require repeat ablations. Achieving stable SR significantly reduces complaints related to the arrhythmia and improves patient clinical status.</AbstractText> |
12,648 | SinoSCORE: a logistically derived additive prediction model for post-coronary artery bypass grafting in-hospital mortality in a Chinese population. | This study aims to construct a logistically derived additive score for predicting in-hospital mortality risk in Chinese patients undergoing coronary artery bypass surgery (CABG). Data from 9839 consecutive CABG patients in 43 Chinese centers were collected between 2007 and 2008 from the Chinese Coronary Artery Bypass Grafting Registry. This database was randomly divided into developmental and validation subsets (9:1). The data in the developmental dataset were used to develop the model using logistic regression. Calibration and discrimination characteristics were assessed using the validation dataset. Thresholds were defined for each model to distinguish different risk groups. After excluding 275 patients with incomplete information, the overall mortality rate of the remaining 9564 patients was 2.5%. The SinoSCORE model was constructed based on 11 variables: age, preoperative NYHA stage III or IV, chronic renal failure, extracardiac arteriopathy, chronic obstructive pulmonary disease, preoperative atrial fibrillation or flutter (within 2 weeks), left ventricular ejection fraction, other elective surgery, combined valve procedures, preoperative critical state, and BMI. In the developmental dataset, calibration using a Hosmer-Lemeshow (HL) test was at P = 0.44 and discrimination based on the area under the receiver operating characteristic curve (ROC) was 0.80. In the validation dataset, the HL test was at P = 0.34 and the area under the ROC (AUC) was 0.78. A logistically derived additive model for predicting in-hospital mortality among Chinese patients undergoing CABG was developed based on the most up-to-date multi-center data from China. |
12,649 | Antiarrhythmic drugs 2013: state of the art. | Antiarrhythmic drugs are widely used, but are of modest efficacy and have important side effects. However, even with the advance of catheter ablation for atrial fibrillation and ventricular tachycardia, antiarrhythmic drugs remain an important tool for treating arrhythmias. Antiarrhythmic drug development has remained slow despite much effort given our limited understanding of what role various ionic currents play in arrhythmogenesis and how they are modified by arrhythmias. This review will focus on promising new antiarrhythmic drugs undergoing clinical investigation or currently approved for clinical use, including amiodarone analogues, agents with novel ionic targets, and new drug combinations. |
12,650 | Common genetic variants in selected Ca²⁺ signaling genes and the risk of appropriate ICD interventions in patients with heart failure. | Defective Ca²⁺ handling in failing cardiomyocites predisposes patients with heart failure (HF) to ventricular arrhythmia. We investigated whether gene variants of Ca²⁺ handling proteins are associated with the occurrence of ventricular tachycardia/fibrillation (VT/VF) in HF patients implanted with a primary prevention implantable cardioverter-defibrillator (ICD).</AbstractText>One hundred thirty-six patients with HF were followed from ICD implantation to the time of first appropriate ICD intervention for VT > 170 bpm. The following polymorphisms were genotyped: ATP2A2 rs1860561 and rs56243033; RYR2 rs4142933; CASQ2 rs4074536; SLC8A1 g.-23449C > A; PLN rs12198461; FKBP1B rs7568163. Hazard ratios (HR) were derived from Cox proportional-hazards regression analysis.</AbstractText>After a mean follow-up of 879 days (IQ range, 327 to 1,459), 34 patients (25%) had appropriate ICD intervention. Non-sustained VT (HR, 2.12; 95%CI, 0.87-5.19; p = 0.09) and atrial fibrillation (AF) at ICD implantation (HR, 2.33; 95%CI, 0.89-6.10; p = 0.08) predicted appropriate ICD interventions with borderline statistical significance. Prevalence of ATP2A2 rs1860561 variant was 17% in patients without VT/VF and 4% in those with ventricular arrhythmia (p = 0.009). After adjustment for AF and NSVT, the rs1860561 A mutant allele independently predicted lower incidence of VT/VF (HR, 0.29; 95%CI, 0.09-0.98; p = 0.04).</AbstractText>The observation that ATP2A2 rs1860561 gene variant associated with lower risk of life-threatening arrhythmia in HF patients suggests that selected calcium gene variants may modify the risk of SD even within the complex and polygenic pathological condition of HF. Combining traditional risk factors and genetic profiling could reveal helpful to identify HF patients who will benefit most from ICD implantation.</AbstractText> |
12,651 | Inactivation of Myosin binding protein C homolog in zebrafish as a model for human cardiac hypertrophy and diastolic dysfunction. | Sudden cardiac death due to malignant ventricular arrhythmia is a devastating manifestation of cardiac hypertrophy. Sarcomere protein myosin binding protein C is functionally related to cardiac diastolic function and hypertrophy. Zebrafish is a better model to study human electrophysiology and arrhythmia than rodents because of the electrophysiological characteristics similar to those of humans.</AbstractText>We established a zebrafish model of cardiac hypertrophy and diastolic dysfunction by genetic knockdown of myosin binding protein C gene (mybpc3) and investigated the electrophysiological phenotypes in this model. We found expression of zebrafish mybpc3 restrictively in the heart and slow muscle, and mybpc3 gene was evolutionally conservative with sequence homology between zebrafish and human mybpc3 genes. Zebrafish with genetic knockdown of mybpc3 by morpholino showed ventricular hypertrophy with increased myocardial wall thickness and diastolic heart failure, manifesting as decreased ventricular diastolic relaxation velocity, pericardial effusion, and dilatation of the atrium. In terms of electrophysiological phenotypes, mybpc3 knockdown fish had a longer ventricular action potential duration and slower ventricular diastolic calcium reuptake, both of which are typical electrophysiological features in human cardiac hypertrophy and heart failure. Impaired calcium reuptake resulted in increased susceptibility to calcium transient alternans and action potential duration alternans, which have been proved to be central to the genesis of malignant ventricular fibrillation and a sensitive marker of sudden cardiac death.</AbstractText>mybpc3 knockdown in zebrafish recapitulated the morphological, mechanical, and electrophysiological phenotypes of human cardiac hypertrophy and diastolic heart failure. Our study also first demonstrated arrhythmogenic cardiac alternans in cardiac hypertrophy.</AbstractText> |
12,652 | Reduction of the inappropriate ICD therapies by implementing a new fuzzy logic-based diagnostic algorithm. | The aim of the study was to analyze the value of a completely new fuzzy logic-based detection algorithm (FA) in comparison with arrhythmia classification algorithms used in existing ICDs in order to demonstrate whether the rate of inappropriate therapies can be reduced.</AbstractText>On the basis of the RR intervals database containing arrhythmia events and controls recordings from the ICD memory a diagnostic algorithm was developed and tested by a computer program. This algorithm uses the same input signals as existing ICDs: RR interval as the primary input variable and two variables derived from it, onset and stability. However, it uses 15 fuzzy rules instead of fixed thresholds used in existing devices. The algorithm considers 6 diagnostic categories: (1) VF (ventricular fibrillation), (2) VT (ventricular tachycardia), (3) ST (sinus tachycardia), (4) DAI (artifacts and heart rhythm irregularities including extrasystoles and T-wave oversensing-TWOS), (5) ATF (atrial and supraventricular tachycardia or fibrillation), and 96) NT (sinus rhythm). This algorithm was tested on 172 RR recordings from different ICDs in the follow-up of 135 patients.</AbstractText>All diagnostic categories of the algorithm were present in the analyzed recordings: VF (n = 35), VT (n = 48), ST (n = 14), DAI (n = 32), ATF (n = 18), NT (n = 25). Thirty-eight patients (31.4%) in the studied group received inappropriate ICD therapies. In all these cases the final diagnosis of the algorithm was correct (19 cases of artifacts, 11 of atrial fibrillation and 8 of ST) and fuzzy rules algorithm implementation would have withheld unnecessary therapies. Incidence of inappropriate therapies: 3 vs. 38 (the proposed algorithm vs. ICD diagnosis, respectively) differed significantly (p < 0.05). VT/VF were detected correctly in both groups. Sensitivity and specificity were calculated: 100%, 97.8%, and 100%, 72.9% respectively for FA and tested ICDs recordings (p < 0.05).</AbstractText>Diagnostic performance of the proposed fuzzy logic based algorithm seems to be promising and its implementation could diminish ICDs inappropriate therapies. We found FA usefulness in correct diagnosis of sinus tachycardia, atrial fibrillation and artifacts in comparison with tested ICDs.</AbstractText>©2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,653 | ECG quantification of myocardial scar and risk stratification in MADIT-II. | Low left ventricular ejection fraction (LVEF) increases risk for both sudden cardiac death (SCD) and for heart failure (HF) death; however, implantable cardioverter-defibrillators (ICDs) reduce the incidence of SCD, not HF death. Distinguishing individuals at risk for HF death (non-SCD) versus SCD could improve ICD patient selection.</AbstractText>This study evaluated whether electrocardiogram (ECG) quantification of myocardial infarction (MI) could discriminate risk for SCD versus non-SCD.</AbstractText>Selvester QRS scoring was performed on 995 MADIT-II trial subjects' ECGs to quantify MI size. MIs were categorized as small (0-3 QRS points), medium (4-7) or large (≥ 8). Mortality, SCD and non-SCD rates in the conventional medical therapy (CMT) arm and mortality and ventricular tachycardia/fibrillation (VT/VF) rates in the ICD arm were analyzed by QRS score group. Both arms were analyzed to determine ICD efficacy by QRS score group.</AbstractText>In the CMT arm, mortality, SCD and non-SCD rates were similar across QRS score groups (P = 0.73, P = 0.92, and P = 0.77). The ICD arm showed similar rates of mortality (P = 0.17) and VT/VF (P = 0.24) across QRS score groups. ICD arm mortality was lower than CMT arm mortality across QRS score groups with greatest benefit in the large scar group.</AbstractText>Recently, QRS score was shown to be predictive of VT/VF in the SCD-HeFT population consisting of both ischemic and nonischemic HF and having a maximum LVEF of 35% versus 30% for MADIT-II. Our study found that QRS score did not add prognostic value in the MADIT-II population exhibiting relatively more severe cardiac dysfunction.</AbstractText>©2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,654 | [Indications for catheter ablation of ventricular tachycardia]. | Ventricular tachyarrhythmias (VT) can cause sudden cardiac death. This can be prevented by an implantable cardioverter-defibrillator (ICD) but approximately 25% of patients with an ICD develop electrical storm (≥ 3 VTs within 24 hours) during the course of 4-5 years. This is a life-threatening event even in the presence of an ICD, particularly if incessant VT is present, and may significantly deteriorate the patient's psychological state if multiple shocks are discharged. Catheter ablation of VT has developed into a standard procedure in many specialized electrophysiology centers. Patients with hemodynamically stable and unstable VT are amendable to substrate-based ablation strategies. Catheter ablation can be performed as emergency procedure in patients with electrical storm as well as electively in patients with monomorphic VT stored in ICD memory. In patients with ischemic or non-ischemic cardiomyopathy, VT ablation is complementary to ICD implantation and can reduce the number of ventricular arrhythmia episodes and shocks and should be performed early. In patients with electrical storm, catheter ablation can acutely achieve rhythm stabilization and may improve prognosis in the long term. Further indications for catheter ablation exist in patients with idiopathic VT where catheter ablation represents a curative therapy, and in patients with symptomatic or asymptomatic frequent premature ventricular beats which may improve prognosis in patients with heart failure and cardiac resynchronization therapy. |
12,655 | [Reverse takotsubo cardiomyopathy-a life-threatening disease. Successful resuscitation of a 31-year-old woman with cardiologic shock after a visit to the dentist]. | We report on a 31-year-old woman requiring resuscitation because of ventricular fibrillation during a standard dental procedure with local anaesthesia. In cardiac ventriculography, reverse takotsubo cardiomyopathy was diagnosed. Because of protracted cardiogenic shock early treatment with calcium sensitizers, as well as the use of an intra-aortic ballon pump (IABP) were necessary to achieve stable hemodynamics. Despite a maximum neuron-specific enolase value of 37.8 ng/ml, the patient was released from the hospital 19 days after admission without a neurological deficit and with completely restored cardiac function. |
12,656 | Hypoxic hepatitis and acute liver failure in a patient with newly onset atrial fibrillation and diltiazem infusion. | Hypoxic hepatitis (HH) most commonly results from haemodynamic instability and disruption of hepatic flow. The vast majority of cases are caused by cardiac failure, respiratory failure and septic shock. We report a case of HH, acute liver failure, acute kidney failure and progressive thrombocytopenia that developed following a hypotensive episode in a patient treated with intravenous diltiazem for a newly developed atrial fibrillation (A-fib). The pre-existing liver diseases, including chronic alcohol use and liver congestion secondary to right heart dysfunction, might have predisposed the patient to the development of HH. The patient was given supportive treatment and experienced full recovery of both liver and kidney function. To our knowledge, this is the first reported case of HH that occurred following ventricular rate control for acute A-fib. For patients with underlying liver diseases, closer blood pressure monitoring is warranted during diltiazem infusion. |
12,657 | Differences of postresuscitation myocardial dysfunction in ventricular fibrillation versus asphyxiation. | This study aims to characterize postresuscitation myocardial dysfunction in 2 porcine models of cardiac arrest (CA): ventricular fibrillation cardiac arrest (VFCA) and asphyxiation cardiac arrest (ACA).</AbstractText>Thirty-two pigs were randomized into 2 groups. The VFCA group (n = 16) were subject to programed electrical stimulation, and the ACA group (n = 16) underwent endotracheal tube clamping to induce CA. Once induced, CA remained untreated for 8 minutes. Two minutes after initiation of cardiopulmonary resuscitation (CPR), defibrillation was attempted until return of spontaneous circulation (ROSC) was achieved or animals died.</AbstractText>Return of spontaneous circulation was 100% successful in VFCA and 50% successful in ACA. Cardiopulmonary resuscitation duration in VFCA was about half as short as in ACA. The survival time of VFCA was significantly longer than that of ACA. Ventricular fibrillation cardiac arrest had better mean arterial pressure, cardiac output, and left ventricular ± dp/dt(max) after ROSC than ACA. Echocardiography revealed significantly lower left ventricular ejection fraction in ACA than in VFCA. Myocardial perfusion imaging using single-photon emission computed tomography demonstrated that myocardial injuries after ACA were more severe and widespread than after VFCA. Under a transmission electron microscope, the overall heart morphologic structure and the mitochondrial crista structure were less severely injured in the VFCA group than in the ACA group. Moreover, the percentage of apoptotic cardiomyocytes was higher in ACA than in VFCA.</AbstractText>Compared with VFCA, ACA causes more severe cardiac dysfunction associated with less successful resuscitation and shorter survival time.</AbstractText>© 2013.</CopyrightInformation> |
12,658 | Atrial remodeling is directly related to end-diastolic left ventricular pressure in a mouse model of ventricular pressure overload. | Atrial fibrillation (AF) is often preceded by underlying cardiac diseases causing ventricular pressure overload.</AbstractText>It was our aim to investigate the progression of atrial remodeling in a small animal model of ventricular pressure overload and its association with induction of AF.</AbstractText>Male mice were subjected to transverse aortic constriction (TAC) or sham operation. After four or eight weeks, echocardiographic measurements and hemodynamic measurements were made and AF induction was tested. The hearts were either fixed in formalin or ventricles and atria were separated, weighed and snap-frozen for RNA analysis.</AbstractText>Four weeks of pressure overload induced ventricular hypertrophy and minor changes in the atria. After eight weeks a significant reduction in left ventricular function occurred, associated with significant atrial remodeling including increased atrial weight, a trend towards an increased left atrial cell diameter, atrial dilatation and increased expression of markers of hypertrophy and inflammation. Histologically, no fibrosis was found in the left atrium. But atrial gene expression related to fibrosis was increased. Minor changes related to electrical remodeling were observed. AF inducibility was not different between the groups. Left ventricular end diastolic pressures were increased and correlated with the severity of atrial remodeling but not with AF induction.</AbstractText>Permanent ventricular pressure overload by TAC induced atrial remodeling, including hypertrophy, dilatation and inflammation. The extent of atrial remodeling was directly related to LVEDP and not duration of TAC per se.</AbstractText> |
12,659 | The pathophysiological relationship and clinical significance of left atrial function and left ventricular diastolic dysfunction in β-thalassemia major. | Iron deposition in combination with inflammatory and immunogenetic factors is involved in the pathophysiology of cardiac dysfunction in β-thalassemia major. We investigated the mechanical and endocrine function of the left atrium and ventricle to identify early signs of dysfunction. We studied 90 patients (mean age: 29 ± 11 years) with β-thalassemia and normal left ventricular function and 90 age and sex-matched healthy controls. Patients and controls underwent a thorough cardiac echocardiographic study and measurements of the b-type (NT-proBNP) and atrial natriuretic peptides (proANP). Patients underwent 24-hr Holter recordings for arrhythmia monitoring. In the patient group, atria were affected early during the course of the disease, prior to diastolic and systolic left ventricular dysfunction. The E/E'ratio (E Doppler mitral fast inflow to the corresponding tissue Doppler E) continually increased with age (P < 0.05) and reached levels indicating left ventricular diastolic dysfunction (E/E' > 15) in the third decade whereas indexes of active and passive atrial function decreased gradually throughout life. In controls, the E/E' ratio continually increased with age but with later (fifth decade) appearance of diastolic dysfunction and a compensatory increase in atrial active function. Both natriuretic peptides were significantly increased in patients compared to controls (558 ± 141 and 2,580 ± 1,830 fmol/mL for NT-proBNP and proANP versus 332 ± 106 and 1,331 ± 1,134 fmol/mL, respectively). Atrial fibrillation was found in a subgroup of 23 (26%) patients, older in age with mild diastolic function and enlarged, depressed atria. In conclusion, atrial mechanical depression seems to be a very early sign of cardiac damage. It may become echocardiographically evident even before diastolic and systolic dysfunction and is associated to supraventricular arrhythmias. |
12,660 | Optimal loop duration during the provision of in-hospital advanced life support (ALS) to patients with an initial non-shockable rhythm. | In advanced life support (ALS), time-cycled "loops" of chest compressions form the basis of action. However, the provider must compromise between interrupting compressions and detecting a change in cardiac rhythm. An "optimal" loop duration would best balance these choices. The current international CPR guidelines recommend 2-min loop durations. The aim of this study was to investigate the "optimal" loop duration in patients with initial asystole or pulseless electrical activity (PEA).</AbstractText>Detailed defibrillator recordings from 249 in-hospital cardiac arrests at the University of Chicago Medicine (Chicago, IL) and St. Olav University Hospital (Trondheim, Norway) were analysed. The clinical states of asystole, PEA, ventricular fibrillation/-tachycardia (VF/VT) and return of spontaneous circulation (ROSC) were annotated along the time axis. PEA and asystole were combined as a single state for the analysis of state development. The probability of staying in PEA/asystole over time was estimated non-parametrically. In addition, to distinguish between initial and secondary PEA/asystole, the latter was defined by the transition from VF/VT or ROSC.</AbstractText>Among patients with initial PEA (n=179), 25% and 50% of patients had left PEA/asystole after 4 and 9 min of ALS efforts, respectively. The corresponding time points for patients with initial asystole (n=70) were 7.3 and 13.3 min, respectively. The probability of transition from secondary PEA/asystole to ROSC or VF/VT varied between 10% and 20% in each 2-4 min interval.</AbstractText>The "optimal" first loop duration may be 4 min in initial PEA and 6-8 min in initial asystole. If secondary PEA/asystole is encountered, 2-min loop duration seems appropriate.</AbstractText>Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,661 | Biphasic versus monophasic defibrillation in out-of-hospital cardiac arrest: a systematic review and meta-analysis. | Biphasic defibrillation is more effective than monophasic one in controlled in-hospital conditions. The present review evaluated the performance of both waveforms in the defibrillation of patients of out-of-hospital cardiac arrest (OHCA) with initial ventricular fibrillation (Vf) rhythm under the context of current recommendations for cardiopulmonary resuscitation.</AbstractText>From inception to June 2012, Medline, Embase, and the Cochrane Central Register of Controlled Trials were searched systemically for randomized controlled trials (RCTs) and observational cohort studies that compared the effects of biphasic and monophasic shocks on Vf termination, return of spontaneous circulation (ROSC), and survival to hospital discharge in OHCA patients with initial Vf rhythm. No restrictions were applied regarding language, population, or publication year.</AbstractText>Four RCTs including 572 patients were identified from 131 potentially relevant references for meta-analysis. The synthesis of these RCTs yielded fixed-effect pooled risk ratios (RRs) for biphasic and monophasic waveforms on Vf termination survival to hospital discharge (RR, 1.14; 95% CI, [0.84-1.54]).</AbstractText>Biphasic waveforms did not seem superior to monophasic ones with respect to Vf termination, ROSC, or survival to hospital discharge in OHCA patients with initial Vf rhythm under the context of current guidelines. However, most trials were conducted in accordance with previous guidelines for cardiopulmonary resuscitation. Therefore, further trials are needed to clarify this issue.</AbstractText>© 2013 Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,662 | Preoperative atrial fibrillation increases risk of thromboembolic events after left ventricular assist device implantation. | Because no series has specifically analyzed the impact of preoperative atrial fibrillation (AF) on patients already at higher risk of thromboembolism after implantation of a left ventricular assist device (LVAD), we review our experience with these patients.</AbstractText>Between July 2003 and September 2011, 389 patients (308 male) underwent implantation of a continuous flow LVAD at University of Michigan Hospital and Mayo Clinic. Median age at implant was 60 years (range, 18 to 79 years). Preoperative AF was present in 120 patients (31%). Outcomes were analyzed for the association of preoperative AF and postoperative thromboembolic (TE) events defined as stroke, transient ischemic attack, hemolysis, or pump thrombosis. Thromboembolic events occurring within the first 30 days were not counted.</AbstractText>One hundred thirty-eight TEs events occurred in 97/389 patients (25%) for an event rate of 0.31 TE events/patient-years of support. Freedom from a TE event in patients with preoperative AF was 62% at 1 year and 46% at 2 years compared with 79% and 72% at 1 and 2 years, respectively, in patients without preoperative AF (p < 0.001). Median survival was 10 months (maximum 7.2 years, total 439 patient-years). Preoperative AF did not decrease late survival at 1 and 2 years after LVAD implant (preop AF: 85% and 70% versus no preop AF: 82% and 70%, respectively; p = 0.55).</AbstractText>Patients with preoperative AF have a lower freedom from TE events after LVAD implant. While overall late survival was not significantly reduced in these patients, refinement in anticoagulation strategies after VAD implant may be required.</AbstractText>Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,663 | Assessment of adequate safety margin using single coupling interval-upper limit of vulnerability test. | Upper limit of vulnerability (ULV) testing using T-wave scanning shocks at multiple coupling intervals correlates well with defibrillation threshold (DFT), but remains underutilized in clinical practice. We measured DFT and ULV at a single coupling interval (SCI), with the aim to identify adequate safety margin at a coupling interval that correlates best with DFT.</AbstractText>Consecutive patients undergoing implantable cardioverter defibrillator implantation underwent simultaneous SCI-ULV and DFT assessment. Following a drive train of 400 ms, a T-wave-coupled shock was delivered. To minimize shocks, patients were randomized to programmed shock at 20 ms before peak (Group I), at peak (Group II), or 20 ms after peak (Group III) of T wave. An initial T-wave test shock at 9 J was followed by ±2 J shocks, until SCI-ULV was ascertained. Device rescue shocks were programmed at test shock +2 J and +4 J shocks followed by external rescue shock.</AbstractText>There were 200 patients: 66 patients in Group I, 67 patients each in Groups II and III; mean age was 68.9 ± 12.4 years; 75% of patients men, 66% with ischemic heart disease and mean ejection fraction of 27.1 ± 7.1%. Overall, the mean number of ventricular fibrillation induction was 1.39 ± 0.8, mean SCI-ULV energy was 7.97 ± 3.39 J, and mean DFT was 8.68 ± 3.19 J. The correlation between SCI-ULV and DFT improved from Group I to Group III and was best in Group III (r(2) = 0.689). There were no major adverse events.</AbstractText>SCI-ULV measured 20 ms after the peak of the T wave correlates well with DFT for assessment of adequate safety margin.</AbstractText>©2013, The Authors. Journal compilation ©2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,664 | Effects of adrenaline on rhythm transitions in out-of-hospital cardiac arrest. | We wanted to study the effects of intravenous (i.v.) adrenaline (epinephrine) on rhythm transitions during cardiac arrest with initial or secondary ventricular fibrillation/tachycardia (VF/VT).</AbstractText>Post hoc analysis of patients included in a randomised controlled trial of i.v. drugs in adult, non-traumatic out-of-hospital cardiac arrest patients who were defibrillated and had a readable electrocardiography recording. Patients who received adrenaline were compared with patients who did not. Cardiac rhythms were annotated manually using the defibrillator data.</AbstractText>Eight hundred and forty-nine patients were included in the randomised trial of which 223 were included in this analysis; 119 in the adrenaline group and 104 in the no-adrenaline group. The proportion of patients with one or more VF/VT episodes after temporary return of spontaneous circulation (ROSC) was higher in the adrenaline than in the no-adrenaline group, 24% vs. 12%, P = 0.03. Most relapses from ROSC to VF/VT in the no-adrenaline group occurred during the first 20 min of resuscitation, whereas patients in the adrenaline group experienced such relapses even after 20 min. Fibrillations from asystole or pulseless electrical activity, shock resistant VF/VT and the number of rhythm transitions per patient was higher in the adrenalin group compared with the no-adrenalin group: 90% vs. 69%, P < 0.001; 46% vs. 33%, P = 0.006; median 8 (5,13) vs. 2 (1,5), P < 0.001, respectively.</AbstractText>Patients who received adrenaline had more rhythm transitions from ROSC and non-shockable rhythms to VF/VT.</AbstractText>© 2013 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.</CopyrightInformation> |
12,665 | Long QT interval in a patient after out-of-hospital cardiac arrest with hypocalcaemia, undergoing therapeutic hypothermia. | A 53-year-old woman was hospitalized after out-of-hospital cardiac arrest due to ventricular fibrillation. Initial electrocardioagram showed sinus rhythm of 117 beats per minute, 452 ms QTc interval, ST-segment depression up to 1 mm in V(2)-V(6), and ST-elevation in lead aVR. Patient was treated with primary coronary angioplasty and therapeutic hypothermia, during which QTc interval prolonged up to 616 ms and Osborn wave was seen in lead V(4), along with elevation of ST-segment in I, II, III, aVF, V(5) and V(6); negative T waves in I, II, aVL, aVF, and V(2)-V(6). Laboratory test results showed hypocalcaemia. After rewarming and ion correction QT abnormalities resolved. |
12,666 | Myocardial contusion and rib fracture repair in an adult horse. | To describe the clinical findings and management of myocardial injury secondary to blunt thoracic trauma and rib fracture in an adult horse.</AbstractText>A 6-year-old Warmblood gelding presented for treatment of blunt thoracic trauma. Sonographic examination of the thorax revealed a complete, mildly comminuted fracture of the left 5th rib with a fragment overlying the left atrium and coronary artery, hemothorax, and subjective left ventricular dyskinesis. Evidence of myocardial injury included atrial fibrillation, ventricular ectopy, and increased plasma cardiac troponin I concentration. The rib fracture was repaired under general anesthesia using a wire and plate technique. The atrial fibrillation converted to normal sinus rhythm coincidentally with intraoperative local infusion of mepivicaine in administration of intercostal perineural analgesia. Continuous, resting, and exercising electrocardiograms, serial cardiac troponin I concentrations and echocardiograms were used to monitor the myocardial injury. The horse was discharged after 5 days of hospitalization. Reexaminations 3 and 15 months after the initial trauma showed healing of the fracture and no evidence of myocardial sequelae.</AbstractText>To our knowledge, this is the first documentation of the diagnosis and monitoring of myocardial injury secondary to blunt thoracic trauma, as well as surgical repair of a rib fracture in an adult horse. Rib fractures and myocardial trauma can be successfully managed in adult horses and myocardial injury should be considered in cases of thoracic trauma.</AbstractText>© Veterinary Emergency and Critical Care Society 2013.</CopyrightInformation> |
12,667 | A combination of P wave electrocardiography and plasma brain natriuretic peptide level for predicting the progression to persistent atrial fibrillation: comparisons of sympathetic activity and left atrial size. | Development of atrial fibrillation (AF) is complexly associated with electrical and structural remodeling and other factors every stage of AF development. We hypothesized that P wave electrocardiography with an elevated brain natriuretic peptide (BNP) level would be associated with the progression to persistence from paroxysmal AF.</AbstractText>P wave electrocardiography such as a maximum P wave duration (MPWD) and dispersion by 12-leads ECG, heart/mediastinum (H/M) ratio by delayed iodine-123 metaiodobenzylguanidine scintigraphic imaging, left ventricular ejection fraction (LVEF), and left atrial dimension (LAD) by echocardiography, and plasma BNP level were measured to evaluate the electrical and structural properties and sympathetic activity in 71 patients (mean ± standard deviation, age: 67 ± 13 years, 63.4 % males) with idiopathic paroxysmal AF.</AbstractText>Over a 12.9-year follow-up period, AF developed into persistent AF in 30 patients. A wider MPWD (>129 ms) (p = 0.001), wider P wave dispersion (>60 ms) (p = 0.001), LAD enlargement (>40 mm) (p = 0.001), higher BNP level (>72 pg/mL) (p = 0.002), lower H/M ratio (≤2.7) (p = 0.025), and lower LVEF (≤60 %) (p = 0.035) were associated with the progression to persistent AF, and the wide MPWD was an independently powerful predictor of the progression to persistent AF with a hazard ratio (HR) of 5.49 [95 % confidence interval (CI) 2.38-12.7, p < 0.0001] after adjusting for potential confounding variables, such as age and sex. The combination of wide MPWD and elevated BNP level was additive and incremental prognostic power with 13.3 [2.16-13, p < 0.0001].</AbstractText>The wide MPWD with elevated BNP level was associated with the progression to persistent AF.</AbstractText> |
12,668 | Atrial fibrillation ablation in octogenarians: where do we stand? | The prevalence of atrial fibrillation increases significantly with age, affecting nearly 10 % of adults greater than 80 years of age. Complications from atrial fibrillation, including stroke, also increase with age. Medical therapy includes anticoagulation, ventricular rate control, and if symptoms persist, maintenance of sinus rhythm with antiarrhythmic drugs. However, anticoagulation and antiarrhythmic therapy is often challenging in the elderly due to side effects, comorbidities, and heightened sensitivity to medications. Catheter based ablation of atrial fibrillation is an effective treatment for paroxysmal atrial fibrillation. However, the major randomized controlled trials, such as Thermocool AF and STOP-AF studies, have excluded the elderly patients. Current guidelines suggest caution when considering ablation for elderly patients due to a lack of available data. We will review recent studies that have observed the outcomes of atrial fibrillation ablation in the elderly, specifically those studies that included octogenarians. |
12,669 | Clinical characteristics and outcomes of patients with grayanotoxin poisoning after the ingestion of mad honey from Nepal. | The aims of this study were to evaluate the clinical characteristics and outcomes of patients with grayanotoxin poisoning due to mad honey brought from Nepal. Medical records of patients with mad honey poisoning admitted to the emergency department between 1 January 2004 and 31 May 2012 were retrospectively reviewed. A total of 15 patients were included in this study. In all patients, mad honey was brought from the Himalayan region of Nepal. The mean age was 52.2 years, and 66.7 % were men. The mean amount of mad honey ingested was 47 cc, and the mean time from ingestion to onset of symptoms was 36 min. In all patients, initial vital signs showed hypotension and bradycardia. The initial electrocardiogram showed sinus bradycardia in eight patients, junctional bradycardia in four patients, complete atrioventricular block in two patients, and atrial fibrillation with slow ventricular response in one patient. Four patients were treated with intravenous normal saline solution only. Eleven patients were treated with intravenous normal saline solution and intravenous atropine sulfate in a dose ranging from 0.5 to 2.0 mg. In all patients, the blood pressure and pulse rate returned to normal limits within 24 h. There were no deaths. The clinical characteristics and outcome of grayanotoxin poisonings caused by the ingestion of mad honey from Nepal are similar with those of mad honey from the Black Sea region of Turkey. |
12,670 | A practical reconstructed phase space approach for ECG arrhythmias classification. | Atrial and ventricular arrhythmias are symptoms of the main common causes of rapid death. The severity of these arrhythmias depends on their occurrence either within the atria or ventricles. These abnormalities of the heart activity may cause an immediate death or cause damage of the heart. In this paper, a new algorithm is proposed for the classification of life threatening cardiac arrhythmias including atrial fibrillation (AF), ventricular tachycardia (VT) and ventricular fibrillation (VF). The proposed technique uses a simple signal processing technique for analysing the non-linear dynamics of the ECG signals in the time domain. The classification algorithm is based upon the distribution of the attractor in the reconstructed phase space (RPS). The behaviour of the ECG signal in the reconstructed phase space is used to determine the classification features of the whole classifier. It is found that different arrhythmias occupy different regions in the reconstructed phase space. Three regions in the RPS are found to be more representative of the considered arrhythmias. Therefore, only three simple features are extracted to be used as classification parameters. To evaluate the performance of the presented classification algorithm, real datasets are obtained from the MIT database. A learning dataset is used to design the classification algorithm and a testing dataset is used to verify the algorithm. The algorithm is designed to guarantee achieving both 100% sensitivity and 100% specificity. The classification algorithm is validated by using 45 ECG signals spanning the considered life threatening arrhythmias. The obtained results show that the classification algorithm attains a sensitivity ranging from 85.7-100%, a specificity ranging from 86.7-100% and an overall accuracy of 95.55%. |
12,671 | In-hospital cardiac complications after intracerebral hemorrhage. | Data on cardiac complications and their precipitants after intracerebral hemorrhage are scarce. We examined the frequency and risk factors for serious in-hospital cardiac events in a large cohort of consecutive intracerebral hemorrhage patients.</AbstractText>A retrospective chart review of 1013 consecutive patients with nontraumatic intracerebral hemorrhage treated at the Helsinki University Central Hospital (2005-2010). We excluded patients with intraparenchymal hematoma related to sub-arachnoid hemorrhage or intracerebral hemorrhage because of fibrinolytic therapies for acute ischemic stroke or myocardial infarction. Serious in-hospital cardiac event was defined as any of in-hospital poststroke acute myocardial infarction, ventricular fibrillation or tachycardia, moderate to serious acute heart failure, or cardiac death.</AbstractText>Among the 948 patients included, ≥1 serious in-hospital cardiac event occurred in 39 (4·1%) patients after a median delay of two-days from stroke onset (acute myocardial infarction in three patients, ventricular fibrillation or tachycardia in three patients, acute heart failure in 36 patients, and cardiac death in three patients). Hospital stay was longer in patients with serious in-hospital cardiac event than in those without (median 12, interquartile range 7-19 vs. 8, 3-14; P = 0·001), with no difference in in-hospital mortality (23·1% vs. 24·3%; P = 0·86). In multivariable logistic regression analysis adjusted for age, gender, and diabetes, atrial fibrillation during hospitalization (odds ratio 6·68 for new-onset atrial fibrillation, 95% confidence interval 2·11-21·18; 4·46 for old atrial fibrillation, 2·08-9·56), and history of myocardial infarction (3·20, 1·18-8·66) were independently associated with serious in-hospital cardiac events.</AbstractText>After intracerebral hemorrhage, 4% of patients suffer an acute serious cardiac complication. Those with history of myocardial infarction or in-hospital atrial fibrillation are at greater risk for such events.</AbstractText>© 2013 The Authors. International Journal of Stroke © 2013 World Stroke Organization.</CopyrightInformation> |
12,672 | CYP2J2 overexpression protects against arrhythmia susceptibility in cardiac hypertrophy. | Maladaptive cardiac hypertrophy predisposes one to arrhythmia and sudden death. Cytochrome P450 (CYP)-derived epoxyeicosatrienoic acids (EETs) promote anti-inflammatory and antiapoptotic mechanisms, and are involved in the regulation of cardiac Ca(2+)-, K(+)- and Na(+)-channels. To test the hypothesis that enhanced cardiac EET biosynthesis counteracts hypertrophy-induced electrical remodeling, male transgenic mice with cardiomyocyte-specific overexpression of the human epoxygenase CYP2J2 (CYP2J2-TG) and wildtype littermates (WT) were subjected to chronic pressure overload (transverse aortic constriction, TAC) or β-adrenergic stimulation (isoproterenol infusion, ISO). TAC caused progressive mortality that was higher in WT (42% over 8 weeks after TAC), compared to CYP2J2-TG mice (6%). In vivo electrophysiological studies, 4 weeks after TAC, revealed high ventricular tachyarrhythmia inducibility in WT (47% of the stimulation protocols), but not in CYP2J2-TG mice (0%). CYP2J2 overexpression also enhanced ventricular refractoriness and protected against TAC-induced QRS prolongation and delocalization of left ventricular connexin-43. ISO for 14 days induced high vulnerability for atrial fibrillation in WT mice (54%) that was reduced in CYP-TG mice (17%). CYP2J2 overexpression also protected against ISO-induced reduction of atrial refractoriness and development of atrial fibrosis. In contrast to these profound effects on electrical remodeling, CYP2J2 overexpression only moderately reduced TAC-induced cardiac hypertrophy and did not affect the hypertrophic response to β-adrenergic stimulation. These results demonstrate that enhanced cardiac EET biosynthesis protects against electrical remodeling, ventricular tachyarrhythmia, and atrial fibrillation susceptibility during maladaptive cardiac hypertrophy. |
12,673 | Shock whilst gardening--implantable defibrillators & lawn mowers. | Electromagnetic interference with implantable cardioverter defibrillators (ICDs) can cause inappropriate shock delivery or temporary inhibition of ICD functions. We present a case of electromagnetic interference between a lawn mower and an ICD resulting in an inappropriate discharge of the device due to erroneous detection of ventricular fibrillation. |
12,674 | Atrial fibrillation and prognosis in patients 80+ years old with chronic heart failure. | It is well known that the prevalence of atrial fibrillation (AF) increases with age. The purpose was to evaluate the impact of AF at the 1-year outcome of patients aged 80? who suffered from chronic heart failure (CHF).</AbstractText>The study included 220 consecutive patients at age 80–92 (mean 82.8 years, 45.5 % men) hospitalized for heart failure. The prospective analysis contains demographic and clinical data, basic laboratory tests with hsTnT and NT-proBNP, 12-lead resting electrocardiogram, echocardiography and coronary angiography results and the number of deaths at the 1-year followup. Patients were analyzed depending on AF in the resting electrocardiogram at hospital entry.</AbstractText>AF was recorded in 52 patients (24 %). The relationship with AF was found for more advanced NYHA class III and IV (p\0.001), higher concentrations of hsCRP (p = 0.0005), hsTnT (p = 0.007) and NT-proBNP (p = 0.0098), higher heart rate in the electrocardiogram (p = 0.000) and longer hospitalization (p = 0.025), older age (p = 0.003) and lower left ventricular ejection fraction (p = 0.006). Annual mortality was 13 % and was higher if AF occurred (17 %). However, there was no association between deaths and AF (p = 0.3297). From the multivariate stepwise analysis, independent risk factors for annual mortality were male gender (OR = 3.432; p = 0.043), left ventricular systolic dimension (OR = 1.871; p = 0.004) and dyslipidemia (OR = 0.252; p = 0.043).</AbstractText>In the oldest patients aged 80? who suffered from CHF, the incidence of atrial fibrillation and annual mortality was high. The independent variables, which enhanced the risk of death at the 1-year follow-up, were male sex and left ventricular systolic dimension, but not atrial fibrillation.</AbstractText> |
12,675 | Efficacy of catheter ablation in nonparoxysmal atrial fibrillation patients with severe enlarged left atrium and its impact on left atrial structural remodeling. | The effect of catheter ablation on severe left atrial enlargement especially in nonparoxysmal atrial fibrillation (NPAF) patients is not well understood. Whether reverse remodelling may occur after ablation has not been evaluated in this setting.</AbstractText>Fifty consecutive patients with left atrial diameter (LAD) ≥50 mm, and LA volume >200 cc undergoing catheter ablation for drug-refractory NPAF were included in this study. Transthoracic echocardiographic measurements were performed at baseline and at 12-months postprocedure. Left ventricular end-diastolic and end-systolic dimensions were indexed by body surface area (LVEDDI, LVESDI). Electroanatomic mapping system (Carto or NavX system) and computed tomography (CT) were used for 3-dimensional reconstruction of the LA. All patients underwent posterior wall isolation and pulmonary vein (PV) antrum and extra PV trigger ablations. Long-term follow-up was monitored by event recordings, 7-day Holter monitors and office visits. The mean age was 65 ± 10 years, 78% male, persistent AF 22 (44%), longstanding AF 28 (56%), LAD diameter 56.9 ± 7.8 mm, left ventricular ejection fraction (LVEF) 53 ± 14 and median AF duration 72 (49-96) months. At 12-month follow-up, 27 patients (54%) remained arrhythmia-free off antiarrhythmic drugs. Significant reduction in LAD at follow-up (≥10% reduction) was observed in 52% (26/50) of the total population and among the 63% (17/27) of recurrence-free patients. Magnitude of LA reduction was identically distributed among the persistent and longstanding persistent AF cohorts (16 ± 12% vs 14 ± 16%, respectively, P = 0.15). A significant 20% improvement in LVEF (from 53 ± 14 to 58 ± 9, P = 0.03) was found in the overall population. Improvement was noted in recurrence-free patients. No significant change in LVEDDI and LVESDI was noted. After adjusting for baseline risk factors in a multivariable model, a reduction in LAD was identified as a strong predictor of long-term success (beta = -11.1, P = 0.013). Preexisting LA scarring was associated with increased LAD (beta = 2.7, P = 0.023). No periprocedural or long-term complications were reported.</AbstractText>Our results show that atrial fibrillation ablation is effective in NPAF patients with severe LA enlargement and is associated with LA reverse remodeling and improvement in LVEF.</AbstractText>© 2013 Wiley Periodicals, Inc.</CopyrightInformation> |
12,676 | Medical and surgical management after spinal cord injury: vasopressor usage, early surgerys, and complications. | The optimal mean arterial blood pressure for maintenance of spinal cord perfusion is not known. Our aim was to describe vasopressor usage and examine their effects in patients with spinal cord injury (SCI). We undertook a retrospective cohort study of 131 patients with SCI who received any kind of vasopressors to maintain blood pressure in the neurocritical care unit of a Level 1 trauma center (2005-2011). Vasopressor usage and complications were obtained from the medical record. Neurological outcomes were evaluated by the American Spinal Injury Association score. Dopamine was the most commonly used vasopressor (48.0%), followed by phenylephrine (45.0%), norepinephrine (5.0%), epinephrine (1.5%), and vasopressin (0.5%). Logistic regression analysis demonstrated that complications (e.g., ventricular tachycardia, troponin elevation, atrial fibrillation, heart rate >130 or <50, etc.) due to vasopressors were independently associated with the overall usages of dopamine (odds ratio [OR] 8.97; p<0.001) and phenylephrine (OR, 5.92; p=0.004), age ≥60 years old (OR, 5.16; p=0.013), and complete SCI (OR, 3.23; p=0.028). There was no difference in neurological improvement with either dopamine (OR, 1.16; p=0.788) or phenylephrine (OR 0.96; p=0.940). Incomplete SCI (OR, 2.64; p=0.019) and surgery <24 h after SCI (OR, 4.25; p=0.025) were independently associated with improved outcome. In summary, vasopressors are associated with increased complications in SCI patients. Further prospective studies are required in order to determine the potential benefits and risks of blood pressure management in patients with SCI. |
12,677 | [Diagnosis and treatment of acute ischemic stroke]. | In Japan, stroke is a major cause of death and serious long-lasting neurological disabilities. Recently, the diagnosis and treatment of ischemic stroke has changed greatly. 1) Patients with TIA are more susceptible to ischemic stroke, and the susceptibility is predicted by the ABCD2score. 2) Brain natriuretic peptide (BNP) is a hormone released from the ventricular myocardium; BNP levels can predict new atrial fibrillation during hospitalization in patients with acute ischemic stroke. 3) In Japan, thrombolysis with intravenous recombinant tissue plasminogen activator (rt-PA) for acute ischemic stroke was approved in 2004, and the time window was extended up to 4.5 h in 2012. 4) Several novel oral anticoagulants (NOAC) have been developed over the last decade; the early initiation of NOACs in acute stroke and TIA patients with nonvalvular atrial fibrillation may be safe. More evidence-based treatment for stroke in Japanese people should be established. |
12,678 | The anti-arrhythmic effects of n-3 PUFAs. | In the past years, in vitro and animal studies have demonstrated several direct and indirect anti-arrhythmic effects of n-3 polyunsaturated fatty acids (n-3 PUFAs), at least in part mediated by anti-oxidant, anti-inflammatory and antifibrotic properties. Several epidemiological and clinical studies have been conducted to investigate the eventual benefits of fish oils in the prevention of cardiovascular diseases. The aim of this paper is to critically review current evidence on the anti-arrhythmic effects of n-3 PUFAs in the prevention of sudden cardiac death (SCD) and atrial fibrillation (AF). Published data are conflicting, but some benefits have been reported in the prevention of SCD after myocardial infarction and of AF, generally after long-course administration. |
12,679 | High-sensitive cardiac troponin T and its relations to cardiovascular risk factors, morbidity, and mortality in elderly men. | Cardiac troponin is emerging as risk indicator in community-dwelling populations. In this study, we investigated the associations of cardiac troponin T (cTnT) to cardiovascular (CV) disease and outcome in elderly men.</AbstractText>Cardiac troponin T was measured using a high-sensitive assay in 940 men aged 71 years participating in the Uppsala Longitudinal Study of Adult Men. We assessed both the cross-sectional associations of cTnT to CV risk factors and morbidities including cancer and the longitudinal associations to outcomes over 10 years of follow-up.</AbstractText>Cardiac troponin T levels were measurable in 872 subjects (92.8%). In the cross-sectional analyses, cTnT was associated to CV risk factors (diabetes, smoking, and obesity), renal dysfunction, CV disease including atrial fibrillation and coronary artery disease, and biomarkers of inflammation and left ventricular dysfunction. In the longitudinal analyses, cTnT independently predicted total mortality and CV events including stroke. The standardized adjusted hazard ratio regarding the composite CV end point was 1.5 (95% CI 1.3-1.8), P < .001, for men with prevalent CV disease and 1.2 (95% CI 1.0-1.4), P = .02, for men without. Cardiac troponin T improved discrimination metrics for all outcomes in the total population. This was mainly driven by the prognostic value of cTnT in subjects with prevalent CV disease.</AbstractText>In community-dwelling men, cTnT levels are associated to CV risk factors and morbidities and predict both fatal and nonfatal CV events. The relations to outcome are mainly seen in men with prevalent CV disease indicating that the prognostic value of cTnT in subjects free from CV disease is limited.</AbstractText>© 2013.</CopyrightInformation> |
12,680 | An organized approach to the localization, mapping, and ablation of outflow tract ventricular arrhythmias. | The outflow tract (OT) regions of the right and left ventricles, common sites of origin for idiopathic ventricular arrhythmias (VA), have complex three-dimensional anatomical relationships. The understanding of in situ or "attitudinal" relationships not only informs the electrocardiographic interpretation of VA site of origin, but also facilitates their catheter-based mapping and ablation strategies. By viewing each patient as his or her own "control," the expected changes in ECG morphology (i.e., frontal plane QRS axis and precordial transition) between adjacent intracardiac structures (e.g., RVOT and aortic root) can be reliably predicted. Successful mapping of OT VAs involve a combination of activation and pacemapping guided by fluoroscopy, electroanatomical mapping, and intracardiac echocardiography. The purpose of this manuscript is to provide a simple, reliable strategy for catheter based mapping and ablation of OT VAs. We also discuss 2 specific challenges in OT VA mapping: (1) differentiating posterior RVOT from right coronary cusp VA origin; and (2) mapping VAs originating from the LV summit. |
12,681 | Vagal modulation of cardiac ventricular arrhythmia. | What is the topic of this review? This article addresses the relationship between vagus nerve activity and malignant ventricular arrhythmias. It focuses on the clinical association of an impaired vagal tone in cardiac disease states with high mortality from sudden cardiac death and the potential underlying mechanisms. What advances does it highlight? The article summarizes the mounting evidence that vagal innervation in the cardiac ventricle plays a key direct role in the prevention of the initiation of ventricular fibrillation. Data are presented on the role that nitric oxide plays in mediating the effects of vagal protection against ventricular fibrillation, supporting the notion that a separate non-muscarinic, nitrergic population of vagal neurons is responsible for this protection. Sudden cardiac death remains a significant unresolved clinical problem, with many of the deaths being due to malignant ventricular arrhythmias. Markers of abnormal autonomic function have been shown to be strong prognostic predictors, highlighting the important relationship between reduced vagal tone and malignant ventricular arrhythmias, such as ventricular fibrillation, in cardiac patients. Exploring the mechanisms underlying the autonomic modulation of ventricular fibrillation, my group has shown that vagus nerve stimulation protects against ventricular fibrillation in the innervated isolated heart preparation. We have provided direct evidence that nitric oxide is released in the ventricle with cervical vagus nerve stimulation and NO mediates the antifibrillatory actions of vagus nerve stimulation in the ventricle. Classical physiology teaches that vagal postganglionic nerves modulate the heart via acetylcholine acting at muscarinic receptors and, dogmatically, that there is little vagal effect in the ventricle, as innervation was believed to be sparse. Mounting evidence from many species now supports the presence of a rich vagal innervation in the ventricle. Data from my group showing that the protective actions of vagus nerve stimulation against ventricular fibrillation and NO release are preserved in the presence of muscarinic block support the notion that a population of nitrergic neurons could be responsible. This potentially exploitable downstream pathway together with the availability of vagus nerve stimulators make it an exciting time to investigate the development of an effective strategy of vagal protection against ventricular fibrillation in the clinical setting. |
12,682 | Global left ventricular longitudinal systolic strain as a major predictor of cardiovascular events in patients with atrial fibrillation. | Although global left ventricular longitudinal systolic strain (GLS) is a sensitive measure of left ventricular mechanics, its relationship with adverse cardiovascular (CV) events in atrial fibrillation (AF) has not been evaluated. This study sought to examine the ability of GLS in predicting CV events in AF.</AbstractText>Observational cohort study.</AbstractText>Department of cardiology in a university hospital.</AbstractText>196 persistent AF patients referred for echocardiographic examination.</AbstractText>The risk of GLS measured by index beat method for CV events was assessed by Cox proportional hazards analyses. CV events were defined as CV death, non-fatal stroke and hospitalisation for heart failure.</AbstractText>There were 19 CV deaths, 12 non-fatal stroke and 28 hospitalisations for heart failure during an average follow-up of 21 ± 10 months. Multivariate analysis showed worsening GLS (HR 1.121; 95% CI 1.023 to 1.228, p=0.014) was independently associated with increased CV events. In direct comparison, GLS outperformed left ventricular ejection fraction (LVEF) and systolic mitral annulus velocity (Sa) in predicting adverse CV events both in univariate and multivariate models (p ≤ 0.043). Besides, the addition of GLS to a Cox model containing chronic heart failure, hypertension, age ≥ 75 years, diabetes, prior stroke score, estimated glomerular filtration rate, LVEF and Sa provided an additional benefit in the prediction of adverse CV events (p=0.022).</AbstractText>GLS was a major parameter and stronger than LVEF and Sa in predicting adverse CV events and could offer an additional prognostic benefit over conventional clinical and echocardiographic systolic parameters in AF.</AbstractText> |
12,683 | Fragmented QRS as a predictor of arrhythmic events in patients with hypertrophic obstructive cardiomyopathy. | This study aims to determine whether fragmented QRS (fQRS) in the surface electrocardiogram (ECG) at implantable cardioverter defibrillator (ICD) implant can predict arrhythmic events using appropriate therapy delivered by the ICD as a surrogate.</AbstractText>Hypertrophic obstructive cardiomyopathy (HOCM) is a genetic disorder associated with life-threatening arrhythmias frequently requiring an ICD. Seeking a noninvasive method of risk stratification remains a challenge.</AbstractText>This paper is a retrospective, multicenter study of patients with HOCM and ICD. Surface 12-lead ECGs were analyzed. Appropriate therapy was validated by a blinded Core Lab. Univariate and multivariate analyses were performed. A p value of <0.05 was considered significant.</AbstractText>We included 102 patients from 13 centers. Mean age at implant was 41.16 ± 18.25 years, 52% were male. Mean left ventricular ejection fraction was 61.56 ± 9.46% and two thirds had heart failure according to the New York Heart Association class I. Secondary prophylaxis ICD implantation was the indication for implant in 40.2% of cases. About half received a single-chamber ICD. fQRS was present at the time of diagnosis in 21 and in 54% at ICD implant. At a mean follow-up of 47.8 ± 39.3 months, 41 patients (40.2%) presented with appropriate therapy. In a multivariate logistic regression, predictors of appropriate therapy included fQRS at implant (odds ratio [OR], 16.4; 95% confidence interval [CI], 3.6-74.0; p = 0.0003), history of combined ventricular tachycardia/fibrillation/sudden death (OR, 14.3; 95% CI, 3.2-69.3; p = 0.001) and history of syncope (OR, 5.5; 95% CI, 1.5-20.4; p = 0.009). Ten deaths (9.8%) occurred during the follow-up. fQRS in the lateral location increased the risk of appropriate therapy (p < 0.0001).</AbstractText>fQRS predicts arrhythmic events in patients with HOCM and should be considered in a model of risk stratification.</AbstractText> |
12,684 | Effectiveness of VF induction with DC fibber versus conventional induction methods in patients on chronic amiodarone therapy. | Amiodarone therapy, especially chronic, can result in difficult ventricular fibrillation (VF) inductions during implantable cardioverter defibrillator (ICD) testing. The efficacy of various VF induction methods on patients treated with amiodarone has not been well described. This prospective analysis evaluated the impact of direct current (DC) fibber, burst fibber, and synchronized T-wave shock VF induction methods.</AbstractText>Data were collected from one study and two enrolling centers totaling 14 ICD patients (92.9 % male, age 64.3 years (range 23.6-81.2)). A minimum of two successful VF inductions from each patient were required to be included in the study analysis. Each VF induction method was attempted in each patient. Non-sustained VF resulting in an aborted shock was considered an induction failure. All 14 patients were on chronic amiodarone therapy.</AbstractText>From a total of 42 attempted inductions, 25 (59.5 %) were successful at inducing VF. The success rates of effective induction of VF during the first attempt using DC, burst, and Shock-on-T are 100, 50, and 28.6 %, respectively. DC fibber had significantly higher VF induction rates than Shock-on-T (p = 0.004) or burst fibber (p = 0.02). There was no difference between Shock-on-T and burst fibber (p = 0.45).</AbstractText>The success rate of VF induction using DC fibber method is significantly higher than either Shock-on-T or burst fibber induction methods for patients on chronic amiodarone therapy. This may facilitate defibrillation threshold testing in such patients.</AbstractText> |
12,685 | Atrial arrhythmia in ageing spontaneously hypertensive rats: unraveling the substrate in hypertension and ageing. | Both ageing and hypertension are known risk factors for atrial fibrillation (AF) although the pathophysiological contribution or interaction of the individual factors remains poorly understood. Here we aim to delineate the arrhythmogenic atrial substrate in mature spontaneously hypertensive rats (SHR).</AbstractText>SHR were studied at 12 and 15 months of age (n = 8 per group) together with equal numbers of age-matched normotensive Wistar-Kyoto control rats (WKY). Electrophysiologic study was performed on superfused isolated right and left atrial preparations using a custom built high-density multiple-electrode array to determine effective refractory periods (ERP), atrial conduction and atrial arrhythmia inducibility. Tissue specimens were harvested for structural analysis.</AbstractText>COMPARED TO WKY CONTROLS, THE SHR DEMONSTRATED: Higher systolic blood pressure (p<0.0001), bi-atrial enlargement (p<0.05), bi-ventricular hypertrophy (p<0.05), lower atrial ERP (p = 0.008), increased atrial conduction heterogeneity (p = 0.001) and increased atrial interstitial fibrosis (p = 0.006) & CD68-positive macrophages infiltration (p<0.0001). These changes resulted in higher atrial arrhythmia inducibility (p = 0.01) and longer induced AF episodes (p = 0.02) in 15-month old SHR. Ageing contributed to incremental bi-atrial hypertrophy (p<0.01) and atrial conduction heterogeneity (p<0.01) without affecting atrial ERP, fibrosis and arrhythmia inducibility. The limited effect of ageing on the atrial substrate may be secondary to the reduction in CD68-positive macrophages.</AbstractText>Significant atrial electrical and structural remodeling is evident in the ageing spontaneously hypertensive rat atria. Concomitant hypertension appears to play a greater pathophysiological role than ageing despite their compounding effect on the atrial substrate. Inflammation is pathophysiologically linked to the pro-fibrotic changes in the hypertensive atria.</AbstractText> |
12,686 | Manifestations of coronary arterial injury during catheter ablation of atrial fibrillation and related arrhythmias. | The prevalence and clinical consequences of coronary arterial injury in a large series of patients undergoing radiofrequency ablation (RFA) of atrial fibrillation (AF) are unknown.</AbstractText>The purpose of this study was to describe the frequency and clinical consequences of coronary arterial injury in a large series of patients undergoing catheter ablation of AF and postablation atrial tachycardia.</AbstractText>The medical records of 5,709 consecutive patients undergoing RFA of AF were reviewed. Heart specimens were also dissected to analyze the course of the coronary arteries.</AbstractText>Arterial injury occurred in 8 patients (0.14%). Three patients developed ventricular fibrillation (VF) due to occlusion of the distal or proximal circumflex (Cx) artery related to RFA in the distal coronary sinus (CS) or base of the LA appendage, respectively. Two VF patients underwent stenting. Five patients developed acute sinus node (SN) dysfunction. In 4/5 patients, the culprit site was subjacent to the SN artery (per computed tomography) coursing over the anterior LA (n = 3) or the septal RA (n = 1). Two patients required a permanent pacemaker. In the heart specimens, the SN artery, after its origin from the proximal Cx artery, coursed along the anterior LA. Also, the proximal Cx artery was found in the atrioventricular groove underneath the base of the LA appendage.</AbstractText>Clinically apparent injury to the coronary arteries during LA ablation for AF is rare. However, it may be associated with potentially life-threatening ventricular arrhythmias and acute SN dysfunction requiring permanent pacing. The culprit sites seem to be in the distal coronary sinus and the anterior LA, and correlate well with the course of the coronary arteries in pathologic specimens. Vigilance and low-power settings are important in minimizing the risk of arterial injury.</AbstractText>© 2013 Heart Rhythm Society. All rights reserved.</CopyrightInformation> |
12,687 | Elevated left ventricular filling pressure estimated by E/E' ratio after exercise predicts development of new-onset atrial fibrillation independently of left atrial enlargement among elderly patients without obvious myocardial ischemia. | To determine whether elevated left ventricular (LV) filling pressure estimated by raised Doppler E velocity to tissue Doppler E' velocity ratio (E/E') after exercise is associated with increased risk of new-onset atrial fibrillation (AF) in non-ischemic elderly patients.</AbstractText>Prognostic importance of exercise induced LV diastolic dysfunction remains uncertain.</AbstractText>We studied 147 elderly patients (73 ± 5 years) who underwent treadmill stress echocardiography. Patients with exercise induced LV wall motion abnormality were not included. Doppler and tissue Doppler measurements were done before treadmill exercise and immediately after the post-stress image acquisition, and E/E' ratio was measured. Raised E/E' was defined as E/E'≥ 15, and left atrial (LA) enlargement was defined as LA volume index ≥ 34 ml/m(2). Using Cox proportional hazards regression analysis, predictor of new-onset AF was determined. Using Kaplan-Meier analysis, we evaluated association between raised post-exercise E/E' or LA enlargement with new-onset AF.</AbstractText>During the follow-up period (median=67 months), there were 25 new-onset AF. Cox proportional hazards regression analysis demonstrated that male gender [hazard ratio (HR) 3.294; p=0.0117], LA enlargement (HR 3.576; p=0.0017), and raised post-exercise E/E' (HR 3147; p=0.0068) were the best predictors of new-onset AF. Kaplan-Meier survival plot demonstrated that patients with both LA enlargement and raised post-exercise E/E' developed new-onset AF most frequently. There was no significant difference in outcome between patients with isolated raised post-exercise E/E' or isolated LA enlargement.</AbstractText>Raised E/E' ratio after exercise provides significant prognostic information for predicting new-onset AF in non-ischemic elderly patients. This prognostic value of raised post-exercise E/E' is independent of and incremental to the LA enlargement.</AbstractText>Copyright © 2013 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.</CopyrightInformation> |
12,688 | Serum potassium levels and the risk of atrial fibrillation: the Rotterdam Study. | Atrial fibrillation is the most common sustained arrhythmia in the elderly. Serum potassium is associated with ventricular arrhythmias and cardiac arrest. Little is known about the association of serum potassium with atrial fibrillation. The objective of this study was to investigate the association of serum potassium and the risk of atrial fibrillation in a population based setting.</AbstractText>The study was performed within the prospective population-based Rotterdam Study. The study population consisted of 4059 participants without atrial fibrillation at baseline for whom baseline levels of serum potassium were measured. Atrial fibrillation was ascertained from centre visit ECG assessments as well as medical records.</AbstractText>During a mean follow up of 11.8 years (SD=5.2 yr), 474 participants developed atrial fibrillation. Participants with hypokalemia (<3.5 mmol/l) had a higher risk of atrial fibrillation (HR: 1.63, 95%CI: 1.03-2.56) than those with normokalemia (3.5-5.0 mmol/l). This association was independent of age, sex, serum magnesium, and other potential confounders. Especially in participants with a history of myocardial infarction, those with hypokalemia had a higher risk of atrial fibrillation than those with normokalemia (HR: 3.81, 95%-CI: 1.51-9.61).</AbstractText>In this study low serum levels of potassium were associated with a higher risk of atrial fibrillation.</AbstractText>© 2013.</CopyrightInformation> |
12,689 | J wave syndromes: molecular and cellular mechanisms. | An early repolarization (ER) pattern in the ECG, consisting of J point elevation, distinct J wave with or without ST segment elevation or slurring of the terminal part of the QRS, was long considered a benign electrocardiographic manifestation. Experimental studies a dozen years ago suggested that an ER is not always benign, but may be associated with malignant arrhythmias. Validation of this hypothesis derives from recent case-control and population-based studies showing that an ER pattern in inferior or infero-lateral leads is associated with increased risk for life-threatening arrhythmias, termed early repolarization syndrome (ERS). Because accentuated J waves characterize both Brugada syndrome (BrS) and ERS, these syndromes have been grouped under the heading of J wave syndromes. BrS and ERS appear to share common ECG characteristics, clinical outcomes, risk factors as well as a common arrhythmic platform related to amplification of Ito-mediated J waves. However, they differ with respect to the magnitude and lead location of abnormal J waves and can be considered to represent a continuous spectrum of phenotypic expression. Recent studies support the hypothesis that BrS and ERS are caused by a preferential accentuation of the AP notch in right or left ventricular epicardium, respectively, and that this repolarization defect is accentuated by cholinergic agonists. Quinidine, cilostazol and isoproterenol exert ameliorative effects by reversing these repolarization abnormalities. Identifying subjects truly at risk is the challenge ahead. Our goal here is to review the clinical and genetic aspects as well as the cellular and molecular mechanisms underlying the J wave syndromes. |
12,690 | Prognostic value of LA volumes assessed by transthoracic 3D echocardiography: comparison with 2D echocardiography. | The hypothesis of this study was that minimal left atrial volume index (LAVImin) by 3-dimensional echocardiography (3DE) is the best predictor of future cardiovascular events.</AbstractText>Although maximal left atrial volume index (LAVImax) by 2-dimensional echocardiography (2DE) is a robust index for predicting prognosis, the prognostic value of LAVImin and the superiority of measurements by 3DE over 2DE have not been determined in a large group of patients.</AbstractText>In protocol 1, we assessed age and sex dependency of LAVIs using 2DE and 3DE in 124 normal subjects and determined their cutoff values (mean + 2 SD). In protocol 2, 2-dimensional (2D) and 3-dimensional (3D) LAVImax/LAVImin were measured in 556 patients with high prevalence of cardiovascular disease. After excluding patients with atrial fibrillation, mitral valve disease, and age <18 years, 439 subjects were followed to record major adverse cardiovascular events (MACE). Patients were divided into 2 groups by the cutoff criteria of LAVI in each method.</AbstractText>In protocol 1, there was no significant age and sex dependency for each 2D and 3D LAVI. In protocol 2, during a mean of 2.5 years of follow-up, MACE developed in 88 patients, including 32 cardiac deaths. Kaplan-Meier survival analyses showed that all 4 LAVI cutoff criteria had significant predictive power of MACE. After variables were adjusted for clinical variables and left ventricular ejection fraction, all 4 methods were still independently and significantly associated with MACE, but 3D-derived LAVImin had the highest risk ratio. 3D LAVImin also had an incremental prognostic value over 3D LAVImax.</AbstractText>LAVIs by both 2DE and 3DE are powerful predictors of future cardiac events. 3D LAVImin tended to have a stronger and additive prognostic value than 3D LAVImax.</AbstractText>Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
12,691 | Protective effect of surfactant inhalation against warm ischemic injury in an isolated rat lung ventilation model. | Warm ischemia-reperfusion injury remains a crucial issue in transplantation following the cardiac death of donors. Previously, we showed that surfactant inhalation during warm ischemia mitigated ischemia-reperfusion injury. This study investigated the mechanisms of surfactant inhalation protection of the warm ischemic lung after reoxygenation with ventilation alone. In an isolated rat lung ventilation model, cardiac arrest was induced in the CTRL (control) and SURF (surfactant treatment) groups by ventricular fibrillation. Ventilation was restarted 110 min later; the lungs were flushed, and a heart and lung block was procured. In the SURF group, a natural bovine surfactant (Surfacten®) was inhaled for 3 min at the end of warm ischemia. In the Sham (no ischemia) group, lungs were flushed, procured, and ventilated in the same way. Afterwards, the lungs were ventilated with room air without reperfusion for 60 min. Surfactant inhalation significantly improved dynamic compliance and airway resistance. Moreover, surfactant inhalation significantly decreased inducible nitric oxide synthase and caspase-3 transcript levels, and increased those of Bcl-2 and surfactant protein-C. Immunohistochemically, lungs in the SURF group showed weaker staining for 8-hydroxy-2'-deoxyguanosine, inducible nitric oxide synthase, and apoptosis, and stronger staining for Bcl-2 and surfactant protein-C. Our results indicate that surfactant inhalation in the last phase of warm ischemia mitigated the injury resulting from reoxygenation after warm ischemia. The reduction in oxidative damage and the inhibition of apoptosis might contribute to the protection of the warm ischemic lungs. |
12,692 | Development of a novel composite stroke and bleeding risk score in patients with atrial fibrillation: the AMADEUS Study. | The aim of the current analysis was to identify independent predictors of the overall clinical outcome of patients with atrial fibrillation (AF), including both stroke/thromboembolism and/or major bleeding. Given the overlap between stroke and bleeding risk factors, a composite risk-stratification score for stroke/thromboembolism or bleeding could potentially be developed.</AbstractText>We used data from the vitamin K antagonist (VKA) arm (n = 2,293; 65% men; mean age 70 ± 9 years) of the AMADEUS (Evaluating the Use of SR34006 Compared to Warfarin or Acenocoumarol in Patients With Atrial Fibrillation) trial, which was a multicenter, randomized, open-label noninferiority study that compared fixed-dose idraparinux with VKA in patients with AF. We defined two composite end points: end point 1 was the combination of stroke/thromboembolism or major bleeding; end point 2 was defined as the combination of stroke, systemic or venous embolism, myocardial infarction, cardiovascular death, or major bleeding.</AbstractText>The independent predictors for composite end point 1 were age (P = .014), previous stroke/transient ischemic attack (P = .049), aspirin use (P = .002), and time in therapeutic range (P = .007). For composite end point 2, similar predictors were evident, plus left ventricular dysfunction (P = .011). Based on the regression models, two novel composite risk-prediction scores were developed and were validated externally in a "real-world" cohort of 441 outpatients with AF receiving anticoagulation treatment. Both composite scores 1 and 2 demonstrated numerically higher discriminatory performance (area under the curve [AUC], 0.728; 95% CI, 0.659-0.798 and AUC, 0.707; 95% CI, 0.655-0.758, for end points 1 and 2, respectively) and a positive net reclassification when compared with currently used risk models (CHADS2 [congestive heart failure, hypertension, age ≥ 75 years, diabetes, prior stroke or transient ischemic attack], CHA2DS2VASc [cardiac failure or dysfunction, hypertension, age ≥ 75 years [doubled], diabetes, stroke (doubled)-vascular disease, age 65 to 74 years, and sex category (female)], and HAS-BLED [hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio, elderly, drugs/alcohol concomitantly]), but the differences were not statistically significant.</AbstractText>We have developed and validated two novel composite scores for stroke/thromboembolism/bleeding that offer good discriminatory and predictive performance. However, these composite risk scores did not perform better than the easier and more practical "traditional" stroke and bleeding risk scores that are currently in use, which allow greater practicality and a more personalized balancing of risks.</AbstractText> |
12,693 | Arrhythmic emergencies in ICCU. | Atrial fibrillation and sustained ventricular arrhythmias are the most common arrhythmias accompanying acute coronary syndromes. Arrhythmias are associated with worse clinical course and increased risk of in-hospital, short-term and long-term mortality in patients with ST-elevation myocardial infarction. This review summarizes the current knowledge on most prevalent arrhythmias in patients with ACS and their management in intensive coronary care unit. |
12,694 | Doppler-derived left ventricular negative dP/dt as a predictor of atrial fibrillation or ischemic stroke in patients with degenerative mitral regurgitation and normal ejection fraction. | The aim of this study was to investigate the role of Doppler-derived left ventricular (LV) -dP/dt in predicting atrial fibrillation (AF) or ischemic stroke in patients with moderate to severe degenerative mitral regurgitation (MR).</AbstractText>Doppler-derived LV -dP/dt was determined from the continuous-wave Doppler spectrum of the MR jet (-dP/dt = 32/time between 3 and 1 m/sec) in 80 patients (mean age 59 ± 16 years, 41% men) with moderate to severe degenerative MR, normal LV ejection fraction (LVEF ≥ 60%), and sinus rhythm at diagnosis. Events were defined as new AF or ischemic stroke.</AbstractText>During a mean follow-up of 18 ± 13 months, there were 9 events (6 new AF, 3 ischemic strokes). Univariate analysis showed that older age, decreased LV -dP/dt, increased LV mass index, and left atrial volume index (LAVI), shortened deceleration time (DT), reduced A' velocity, and elevated E/E' ratio, prolongation of pulmonary venous (PV) atrial reversal (AR) flow duration relative to mitral inflow A-wave duration (AR-Adur) were associated with events. In multivariate Cox regression analysis, Doppler-derived LV -dP/dt (for each 100 mmHg/sec increase, hazard ratio: 0.165, 95% confidence interval: 0.036-0.761, P = 0.021) and E/E' (hazard ratio: 0.820, 95% confidence interval: 0.682-0.987, P = 0.036) were significant independent predictors of AF or ischemic stroke.</AbstractText>Doppler-derived LV -dP/dt is independently associated with the occurrence of AF or ischemic stroke in patients with moderate to severe degenerative MR and provides additional prognostic information.</AbstractText>© 2013, Wiley Periodicals, Inc.</CopyrightInformation> |
12,695 | Peripheral cardiac sympathetic hyperactivity in cardiovascular disease: role of neuropeptides. | High levels of sympathetic drive in several cardiovascular diseases including postmyocardial infarction, chronic congestive heart failure and hypertension are reinforced through dysregulation of afferent input and central integration of autonomic balance. However, recent evidence suggests that a significant component of sympathetic hyperactivity may also reside peripherally at the level of the postganglionic neuron. This has been studied in depth using the spontaneously hypertensive rat, an animal model of genetic essential hypertension, where larger neuronal calcium transients, increased release and impaired reuptake of norepinephrine in neurons of the stellate ganglia lead to a significant tachycardia even before hypertension has developed. The release of additional sympathetic cotransmitters during high levels of sympathetic drive can also have deleterious consequences for peripheral cardiac parasympathetic neurotransmission even in the presence of β-adrenergic blockade. Stimulation of the cardiac vagus reduces heart rate, lowers myocardial oxygen demand, improves coronary blood flow, and independently raises ventricular fibrillation threshold. Recent data demonstrates a direct action of the sympathetic cotransmitters neuropeptide Y (NPY) and galanin on the ability of the vagus to release acetylcholine and control heart rate. Moreover, there is as a strong correlation between plasma NPY levels and coronary microvascular function in patients with ST-elevation myocardial infarction being treated with primary percutaneous coronary intervention. Antagonists of the NPY receptors Y1 and Y2 may be therapeutically beneficial both acutely during myocardial infarction and also during chronic heart failure and hypertension. Such medications would be expected to act synergistically with β-blockers and implantable vagus nerve stimulators to improve patient outcome. |
12,696 | Amplitude spectrum area to guide resuscitation-a retrospective analysis during out-of-hospital cardiopulmonary resuscitation in 609 patients with ventricular fibrillation cardiac arrest. | The capability of amplitude spectrum area (AMSA) to predict the success of defibrillation (DF) was retrospectively evaluated in a large database of out-of-hospital cardiac arrests.</AbstractText>Electrocardiographic data, including 1260 DFs, were obtained from 609 cardiac arrest patients due to ventricular fibrillation. AMSA sensitivity, specificity, accuracy, and positive and negative predictive values (PPV, NPV) for predicting DF success were calculated, together with receiver operating characteristic (ROC) curves. Successful DF was defined as the presence of spontaneous rhythm ≥40bpm starting within 60s from the DF. In 303 patients with chest compression (CC) depth data collected with an accelerometer, changes in AMSA were analyzed in relationship to CC depth.</AbstractText>AMSA was significantly higher prior to a successful DF than prior to an unsuccessful DF (15.6±0.6 vs. 7.97±0.2mV-Hz, p<0.0001). Intersection of sensitivity, specificity and accuracy curves identified a threshold AMSA of 10mV-Hz to predict DF success with a balanced sensitivity, specificity and accuracy of almost 80%. Higher AMSA thresholds were associated with further increases in accuracy, specificity and PPV. AMSA of 17mV-Hz predicted DF success in two third of instances (PPV of 67%). Low AMSA, instead, predicted unsuccessful DFs with high sensitivity and NPV >97%. Area under the ROC curve was 0.84. CC depth affected AMSA value. When depth was <1.75in., AMSA decreased for consecutive DFs, while it increased when the depth was >1.75in. (p<0.05).</AbstractText>AMSA could be a useful tool to guide CPR interventions and predict the optimal timing of DF.</AbstractText>Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
12,697 | Effect of atrial fibrillation ablation on myocardial function: insights from cardiac magnetic resonance feature tracking analysis. | Restoration of sinus rhythm may result in an improvement of left heart function in patients with atrial fibrillation (AF). Cardiovascular magnetic resonance (CMR) feature tracking (FT) technique may help detect subtle wall-motion abnormalities. Consequently this study aimed to analyse existence and reversibility of subclinical cardiac dysfunction following atrial fibrillation ablation. 28 consecutive patients (mean age 61 years) with paroxysmal AF underwent pulmonary vein isolation. CMR imaging was done 3 (±3) days before and 3.4 (±1.1) months after ablation. Left heart function was determined by performing FT analysis. Statistical analysis included paired student's t test, random effects metaanalysis to assess the cohort's health status and Bland-Altman analysis. 17 patients (61%) were free from AF at follow-up. Bland-Altman analysis showed good coefficients of variation. Of all 195 parameters, 27 changed (14%): 9 improved significantly (5%), 12 worsened significantly (6%), whereas 6 parameters worsened not significantly (3%). 18 of 120 systolic parameters changed (15%), 14 worsened (12%), 4 improved (3%). In 9 of 75 diastolic parameters, values changed (12%): 5 improved (7%) and 4 worsened (5%). Meta-analysis revealed that our collective's FT values at baseline didn't differ significantly from healthy volunteers' values [Q values of 0.01 (p value 0.921) and 1.499 (p value 0.221)]. AF patients undergoing ablation appear to have near normal cardiac wall motion, which does not improve following successful ablation. Feature tracking analysis is a reliable tool to determine treatment effects but is more likely to show positive findings if the population is unhealthy. |
12,698 | Cardiac perforation from implantable cardioverter-defibrillator lead placement: insights from the national cardiovascular data registry. | Cardiac perforation is a feared complication of implantable cardioverter-defibrillator (ICD) lead implantation because of the potential for significant morbidity and mortality. Predictors of perforation and the severity of associated adverse events have not been well studied. We sought to identify predictors of cardiac perforation from ICD lead implantation and subsequent outcomes.</AbstractText>We studied 440 251 first-time ICD recipients in the ICD Registry implanted between January 2006 and September 2011. Using hierarchical multivariable logistic regression adjusting for patient, implanting physician, and hospital characteristics, we examined the predictors of perforation and the association of perforation with other major complications, length of stay, and in-hospital mortality. Cardiac perforation occurred in 625 patients (0.14%). After multivariable adjustment, older age, female sex, left bundle branch block, worsened heart failure class, higher left ventricular ejection fraction, and non-single-chamber ICD implant were associated with a greater odds of perforation. Conversely, atrial fibrillation, diabetes mellitus, previous cardiac bypass surgery, and higher implanter procedural volume were associated with a lower odds of perforation (all P<0.05). After adjustment, ICD recipients with perforation had greater odds of other associated major complications (odds ratio, 27.5; 95% confidence interval, 19.9-38.0; P<0.0001), postprocedural hospital stays >3 days (odds ratio, 16.3; 95% confidence interval, 13.7-19.4; P<0.0001), and in-hospital death (odds ratio, 17.7; 95% confidence interval, 12.2-25.6; P<0.0001).</AbstractText>In a large population of ICD recipients, specific patient and implanter characteristics predicted cardiac perforation risk. Cardiac perforation was associated with a substantially increased risk of other major complications, prolonged hospital stays, and death.</AbstractText> |
12,699 | External defibrillation failure due to antimicrobial incise drape. | Antimicrobial incise drapes adhere to a patient's skin during surgery in an attempt to reduce surgical infections. We describe a patient undergoing repeated aortic valve replacement who experienced sudden ventricular fibrillation before median sternotomy. External defibrillation was unsuccessful on multiple attempts using several defibrillators. On removal of the incise drape from the patient's chest, external defibrillation was immediately successful. Increased transthoracic impedance can be caused by multiple factors and may prevent defibrillation. To our knowledge, this is the first reported case of an antimicrobial incise drape preventing defibrillation. If external defibrillation, cardioversion, or pacing is indicated intraoperatively, we recommend prompt removal of the antimicrobial incise drapes before electrode placement if the drapes overlay the intended pad position. Since this case, our institutional practice has now changed to placement of 2 external adhesive defibrillator electrodes onto the patient's skin lateral to the surgical field before incise drape application to allow for defibrillation. |
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