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13,400 | Implantable cardioverter defibrillator therapy in paediatric practice: a single-centre UK experience with focus on subcutaneous defibrillation. | Sudden cardiac death (SCD) risk can be managed by implantable cardioverter defibrillators (ICD). Defibrillation shocks can be delivered via ICD generator and/or intracardiac or subcutaneous coil configurations. We present our single-centre use of childhood ICDs.</AbstractText>Twenty-three patients had ICD implantation, with median age and weight of 12.96 years and 41.35 kg. Indications included eight long QT; four hypertrophic cardiomyopathy; three Brugada syndrome; two idiopathic ventricular fibrillation; two post-congenital heart repair; two family history of SCD with abnormal repolarization; one catecholaminergic polymorphic ventricular tachycardia; and one left ventricle non-compaction. Twelve had out of hospital cardiac arrests prior to implantation. Techniques included 13 conventional ICD implants (pre-pectoral device with endocardial leads), 7 with subcutaneous defibrillation coils (sensing via epicardial or endocardial leads tunnelled to the ICD), and 3 with exclusive subcutaneous ICD (sensing and defibrillation via the same subcutaneous lead). Satisfactory defibrillation efficacy and ventricular arrhythmia sensing was confirmed at implantation. Follow-up ranged from 0.17 to 11.08 years. One child died with the ICD in situ. Ten children received appropriate shocks; five on more than one occasion. Five received inappropriate shocks (for inappropriate recognition of sinus tachycardia or supraventricular tachycardia). Five children underwent six further interventions; all had intracardiac leads.</AbstractText>Innovative shock delivery systems can be used in children requiring an ICD. The insertion technique and device used need to accommodate the age and weight of the child, and concomitant need for pacing therapy. We have demonstrated effective defibrillation with shocks delivered via configurations employing subcutaneous coils in children.</AbstractText> |
13,401 | Early onset of cooling catheter-related right atrial thrombus following cardiac arrest. | Catheter-related right atrial thrombus (RAT) is an uncommon life-threatening complication. Few cases of endovascular cooling catheter–related complications have been reported. We report the first case of endovascular cooling catheter–related RAT. A 17-year-old adolescent boy was treated with therapeutic hypothermia using an endovascular cooling catheter following ventricular fibrillation cardiac arrest. He became alert, but RAT was found 3 days after the placement of the cooling catheter. Anticoagulation with enoxaparin for 2 weeks completely resolved the RAT, and he was consequently treated with radiofrequency ablation and received an implanted cardiac defibrillator. This case report highlights the occurrence of endovascular cooling catheter–related RAT early after the placement of a catheter. Physicians should monitor whether RAT occurs during and following therapeutic hypothermia with a cooling catheter. |
13,402 | Mitral valve replacement combined with coronary artery bypass graft surgery in patients with moderate-to-severe ischemic mitral regurgitation. | Ischemic mitral regurgitation (IMR) is associated with increased mortality. Even after coronary artery bypass grafting (CABG), IMR reduces survival. Several studies have shown increased perioperative mortality for mitral valve replacement (MVR) in this situation, but the subject remains controversial.</AbstractText>To investigate the impact of MVR on immediate outcomes in patients with moderate-to-severe IMR undergoing concomitant CABG compared with those undergoing CABG only.</AbstractText>We performed a retrospective study of 42 patients undergoing CABG+MVR (n=16) or CABG only (n=26) at the Division of Cardiovascular Surgery of PROCAPE, between May 2007 and April 2010. Preoperative clinical characteristics, procedural characteristics, major and minor complications after surgery, preoperative and postoperative left ventricular ejection fraction (LVEF) by echocardiography, and outcome (survivor or death) were assessed.</AbstractText>Mean patient age was 63.4 ± 8.5 years, and 64.8% (n=23) were male. The CABG+MVR group showed lower rates of postoperative low cardiac output (6.3% vs. 42.3%, p=0.014) and atrial fibrillation (6.3% vs. 38.5%, p=0.021). Both groups had higher mean LVEF in the postoperative compared with the preoperative period, but the average gain in LVEF in the CABG+MVR group was higher than in the CABG-only group (8.88 ± 2.39 vs. 4.31 ± 1.23, p<0.001). There was no significant difference in operative mortality (6.3% vs. 7.7%, p=0.679).</AbstractText>CABG+MVR can be performed safely in patients with moderate-to-severe IMR. CABG+MVR resulted in lower rates of complications than CABG only. Both surgical approaches resulted in significant improvement of postoperative LVEF. However, there was greater improvement in the CABG+MVR group.</AbstractText>Copyright © 2012 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.</CopyrightInformation> |
13,403 | Left ventricular fibrosis in atrial fibrillation. | Excessive atrial fibrosis is involved in the pathogenesis of atrial fibrillation (AF), but little is known of left ventricular (LV) fibrotic status in patients with AF. In the present study, we investigated the presence of abnormal LV fibrosis in AF, its effect on cardiac function, a possible association with arterial stiffness (i.e., systemic cardiovascular fibrosis), and the parameters of endothelial activation, dysfunction, and damage. We also studied whether LV fibrosis could be linked to the future risk of AF onset. In a cross-sectional study, the severity of LV fibrosis was assessed by echocardiographic acoustic densitometry in patients with permanent AF (n = 49), patients with paroxysmal AF (n = 44), AF-free "disease controls" (n = 42) and "healthy controls" (n = 48). Arterial stiffness (pulse wave velocity), plasma markers of endothelial activation (E-selectin), endothelial damage/dysfunction (von Willebrand factors), and microvascular endothelial function (laser Doppler flowmetry) were quantified. In a longitudinal study, 93 patients with pacemakers (22 with AF) were followed up for ≥1 year to assess the predictive value of LV fibrosis for the development of new-onset AF. More severe LV fibrosis was present in both paroxysmal and permanent AF than in the AF-free controls (p <0.001), with more LV fibrosis in permanent than in paroxysmal AF (p = 0.002). The severity of LV fibrosis in AF wais independently associated with diastolic dysfunction (p = 0.03), but not with LV contractility, arterial stiffness, or endothelial damage/dysfunction. In conclusion, LV fibrosis might contribute to LV diastolic dysfunction and the high prevalence of heart failure with preserved ejection fraction in subjects with AF. |
13,404 | Quantification of transmembrane currents during action potential propagation in the heart. | The measurement, quantitative analysis, theory, and mathematical modeling of transmembrane potential and currents have been an integral part of the field of electrophysiology since its inception. Biophysical modeling of action potential propagation begins with detailed ionic current models for a patch of membrane within a distributed cable model. Voltage-clamp techniques have revolutionized clinical electrophysiology via the characterization of the transmembrane current gating variables; however, this kinetic information alone is insufficient to accurately represent propagation. Other factors, including channel density, membrane area, surface/volume ratio, axial conductivities, etc., are also crucial determinants of transmembrane currents in multicellular tissue but are extremely difficult to measure. Here, we provide, to our knowledge, a novel analytical approach to compute transmembrane currents directly from experimental data, which involves high-temporal (200 kHz) recordings of intra- and extracellular potential with glass microelectrodes from the epicardial surface of isolated rabbit hearts during propagation. We show for the first time, to our knowledge, that during stable planar propagation the biphasic total transmembrane current (I(m)) dipole density during depolarization was ∼0.25 ms in duration and asymmetric in amplitude (peak outward current was ∼95 μA/cm(2) and peak inward current was ∼140 μA/cm(2)), and the peak inward ionic current (I(ion)) during depolarization was ∼260 μA/cm(2) with duration of ∼1.0 ms. Simulations of stable propagation using the ionic current versus transmembrane potential relationship fit from the experimental data reproduced these values better than traditional ionic models. During ventricular fibrillation, peak I(m) was decreased by 50% and peak I(ion) was decreased by 70%. Our results provide, to our knowledge, novel quantitative information that complements voltage- and patch-clamp data. |
13,405 | Transthoracic delivery of large devices into the left ventricle through the right ventricle and interventricular septum: preclinical feasibility. | We aim to deliver large appliances into the left ventricle through the right ventricle and across the interventricular septum. This transthoracic access route exploits immediate recoil of the septum, and lower transmyocardial pressure gradient across the right versus left ventricular free wall. The route may enhance safety and allow subxiphoid rather than intercostal traversal.</AbstractText>The entire procedure was performed under real-time CMR guidance. An "active" CMR needle crossed the chest, right ventricular free wall, and then the interventricular septum to deliver a guidewire then used to deliver an 18Fr introducer. Afterwards, the right ventricular free wall was closed with a nitinol occluder. Immediate closure and late healing of the unrepaired septum and free wall were assessed by oximetry, angiography, CMR, and necropsy up to four weeks afterwards.</AbstractText>The procedure was successful in 9 of 11 pigs. One failed because of refractory ventricular fibrillation upon needle entry, and the other because of inadequate guidewire support. In all ten attempts, the right ventricular free wall was closed without hemopericardium. There was neither immediate nor late shunt on oximetry, X-ray angiography, or CMR. The interventricular septal tract fibrosed completely. Transventricular trajectories planned on human CT scans suggest comparable intracavitary working space and less acute entry angles than a conventional atrial transseptal approach.</AbstractText>Large closed-chest access ports can be introduced across the right ventricular free wall and interventricular septum into the left ventricle. The septum recoils immediately and heals completely without repair. A nitinol occluder immediately seals the right ventricular wall. The entry angle is more favorable to introduce, for example, prosthetic mitral valves than a conventional atrial transseptal approach.</AbstractText> |
13,406 | Epidemiology of pediatric critically-ill patients presenting to the pediatric emergency department. | This study aimed to analyze the epidemiologic patterns of pediatric critically-ill patients presenting to the emergency department (ED) and the etiologies of intensive care unit (ICU) admission of different age groups.This retrospective study of all children aged less than 18 years presenting with critical illnesses to the ED was conducted in a tertiary medical center in Taiwan from 2003 to 2007. All patients transferred to the ICU from the ED were included without distinction. Demographic data of critically-ill children admitted to the ED and ICU were analyzed. Etiologies of the ICU admissions were analyzed by various age groups.There were 2978 critically-ill children admitted to the ICU from the ED. In 120 pediatric patients with out-of-hospital cardiac arrest, cases with pulseless electrical activity or ventricular fibrillation had higher successful CPR rates than patients with asystole (both p<0.05). In patients admitted to ICUs, complications from the perinatal period, respiratory system diseases, accidental injuries and poisoning were the predominant etiologies respectively in young children (42.5%), school-aged children (38.5%), and adolescents (47.9%). Moreover, the most common of which was respiratory distress syndrome in neonates followed by bacterial pneumonia and status epilepticus.Epidemiologic analysis may provide primary clinicians to identify significant differences in admission rates based on different etiologies of various age groups. |
13,407 | IVC diameter in patients with chronic heart failure: relationships and prognostic significance. | The aim of this study was to assess the relation between inferior vena cava (IVC) diameter, clinical variables, and outcome in patients with chronic heart failure (HF).</AbstractText>The IVC distends as right atrial pressure rises. Therefore it might represent an index of HF severity independent of left ventricular ejection fraction (LVEF). The relation between IVC diameter and other clinical variables and its prognostic significance in patients with HF has not been explored.</AbstractText>Outpatients attending a community HF service between 2008 and 2010 were enrolled. Heart failure was defined as the presence of relevant symptoms and signs and objective evidence of cardiac dysfunction: either LVEF <45% or the combination of both left atrial dilation (≥4 cm) and raised amino-terminal pro-brain natriuretic peptide (NT-proBNP) ≥400 pg/ml. Patients were followed for a median of 567 (interquartile range: 413 to 736) days. The primary composite endpoint was cardiovascular death and HF hospitalization.</AbstractText>Among the 693 patients enrolled, median age was 73 years, 33% were women, and 568 had HF. Patients with HF in the highest tertile of IVC diameter were older; had lower body mass index; were more likely to have atrial fibrillation and to be treated with diuretics; and had larger left atrial volumes, higher pulmonary pressures, and less negative values for global longitudinal strain. The LVEF and systolic blood pressure were similar across tertiles of IVC diameter. The IVC diameter and log [NT-proBNP] were correlated (r = 0.55, p < 0.001). During follow-up, 158 patients reached a primary endpoint. In a multivariable Cox regression model, including NT-proBNP, only increasing IVC diameter, urea, and the trans-tricuspid systolic gradient independently predicted a poor outcome. Neither global longitudinal strain nor LVEF were adverse predictors.</AbstractText>In patients with chronic HF with or without a reduced LVEF, increasing IVC diameter identifies patients with an adverse outcome.</AbstractText>Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,408 | Blood in, blood out: left ventricular pseudoaneurysm following mitral valve endocarditis. | A 76-year old male on warfarin due to atrial fibrillation was admitted with Staphylococcus aureus septicaemia. Echocardiography demonstrated mitral valve endocarditis, and shortly thereafter, he suffered an intracranial haemorrhage as a result of septic embolism. Four weeks later, cardiac magnetic resonance imaging revealed a newly formed pseudoaneurysm. A left ventricular pseudoaneurysm caused by infective endocarditis is very rare, but awareness of this unusual complication may allow surgery to prevent rupture. |
13,409 | A serious cause of panic attack. | We report on a case of a patient with atrial fibrillation in the setting of Wolff-Parkinson-White syndrome. The patient underwent synchronized electrical cardioversion, typically considered safe and effective, which resulted in a dangerous complication for the patient (degeneration into ventricular fibrillation). Discussion of common rhythm disturbances in WPW and management strategies are reviewed. |
13,410 | Clinical relevance of slow ventricular tachycardia in heart failure patients with primary prophylactic implantable cardioverter defibrillator indication. | Implantable cardioverter defibrillators (ICDs) have shown to reduce all-cause mortality in heart failure patients. In SCD-HeFT study, ICDs were programmed with a detection zone of ≥ 187 b.p.m. Thus, the incidence and clinical significance of slower ventricular tachycardias (VTs) in these patients remains largely unknown, though clinically important for device selection, programming, and follow-up.</AbstractText>We prospectively studied symptomatic heart failure patients with an indication for a primary prophylactic ICD with or without concomitant resynchronization therapy according to SCD-HeFT inclusion criteria. Devices were programmed to an additional monitor zone for slow VTs at heart rates 130-186 b.p.m. Two hundred consecutive patients (86% male) were followed for a mean of 509 ± 308 days. One hundred and thirty-seven patients (68.5%) were New York Heart Association class III, 75 patients (37.5%) were on cardiac resynchronization therapy, and 124 (62%) had ischaemic cardiomyopathy. We observed 473 VT episodes in 36 patients (18%) and 131 ventricular fibrillation episodes in 30 patients (15%). Ventricular tachycardia overall occurred in 40 patients (20%). The incidence of slow VTs was low in only 12 patients (6%). No patient with slow VT suffered from syncope, palpitation, or decompensation leading to hospitalization. We did not find any reliable predictor for increased long-term risk of slow VTs.</AbstractText>Incidence of slow VTs in a typical heart failure population with primary prophylactic ICD-implantation ± resynchronization therapy is very low. Slow VTs detected in the ICD monitor zone remained clinically asymptomatic. Thus, single chamber and atriobiventricular ICDs with a VT/ventricular fibrillation zone of ≥ 187 b.p.m. and one burst before shock delivery might be sufficient and pragmatic for the vast majority of these patients.</AbstractText> |
13,411 | [Assessment of diastolic heart failure. Current role of echocardiography]. | Diastolic heart failure, also known as heart failure with preserved left ventricular ejection fraction (HF-pEF), is responsible for approximately 50 % of all heart failure cases. According to current guidelines the diagnosis HF-pEF requires three criteria: (1) signs or symptoms of heart failure, (2) presence of a normal left ventricular ejection fraction and (3) evidence of diastolic dysfunction. Echocardiography is the diagnostic modality of choice, especially after ruling out other causes of dyspnea, such as pulmonary diseases, heart rhythm disturbances and volume overload. Important echocardiographic parameters for the assessment of diastolic function are atrial dimensions, myocardial mass, mitral inflow pattern, pulmonary vein flow, propagation velocity of mitral inflow and the tissue Doppler of the mitral annulus. Nevertheless, a complete echocardiographic examination should be performed in every patient with heart failure. In general, diastolic dysfunction is frequently associated with increased atrial diameter and left ventricular hypertrophy. In advanced stages pulmonary hypertension can be present. A robust method for evaluation of systolic function in patients with diastolic dysfunction is crucial. The mitral inflow pattern provides various parameters to describe diastolic function (E/A ratio, deceleration time, isovolumetric relaxation time). In case of difficulties to separate a normal from a pseudonormal mitral inflow pattern the Valsalva maneuver can be used. Another valuable parameter for this differentiation is the duration of the backward flow in the pulmonary veins in contrast to forward flow over the mitral valve. Tachycardia or atrial fibrillation is a major problem for grading of diastolic function; however, in patients with atrial fibrillation E/e' is a well-established parameter. In summary, this review provides a detailed overview and discussion of the established and newer echocardiography techniques for the evaluation of diastolic function and provides an algorithm for the assessment of diastolic dysfunction in everyday routine. |
13,412 | Current state of cardiac amyloidosis. | Cardiac amyloidosis, an infiltrative restrictive cardiomyopathy once thought to be universally fatal, is now increasingly recognized as less rare than previously thought. This update is intended to provide a review of newer aspects of the presentation, diagnosis and treatment of cardiac amyloidosis.</AbstractText>Amyloid involvement of the heart is increasingly seen, especially in the elderly population. Recent data suggest life expectancy has increased from 6 to 16-20 months in the most common subtype, AL amyloid. The clinical presentation is typically one of heart failure in the setting of normal or low normal ejection fraction, inappropriate ventricular hypertrophy and atrial enlargement with or without atrial fibrillation. Diagnosis is now most often made by cardiac MRI, with 2D echocardiography serving more of a screening role in patients with heart failure or a similar family history. The gold standard diagnostic test is right-ventricular biopsy, which demonstrates positivity for Congo Red staining. Due to a propensity for disease progression, typically low systemic blood pressure, frequent extra-cardiac involvement and autonomic dysfunction, cardiac amyloidosis is difficult to treat due to poor tolerance of most cardiovascular medication and poor outcome for transplantation. Newer therapies such as bortezomib, usually given to patients with multiple myeloma and serum light chains, are promising in controlling amyloidosis.</AbstractText>Recent advances in diagnosis and treatment of amyloid are associated with improved prognosis. Newer therapies offer future benefits.</AbstractText> |
13,413 | Relationship of left ventricular size to left atrial and left atrial appendage size in sinus rhythm patients with dilated cardiomyopathy. | Thromboembolic events are a frequent cause of mortality in patients with congestive heart failure. The aim of or study was to evaluate the relationship of left ventricular end diastolic diameter (LVEDD) to left atrial (LA) size and left atrial appendage (LAA) size in patients with dilated cardiomyopathy in sinus rhythm, as well as to determine the prevalence of thrombi in LV and LA /LAA.</AbstractText>This was a prospective cross-sectional study, conducted from December 2009 until December 2011. The study included 95 patients with dilated cardiomyopathy in sinus rhythm. Patients with swallowing problems, acute myocardial infarction, atrial fibrillation/flatter, severe systolic dysfunction, and/or patients who were taking oral anticoagulation therapy were excluded.</AbstractText>Mean patient age was 58.6 ± 12.2 years and 68.4% were men. Mean LVEDD of our population was 66.5 ± 6.5 mm, while mean LA atrium, LA volume and LAA maximal area were 46 ± 5.1 mm, 87.2 ± 38.7 cm(3) and 4.7 ± 1.2 cm(2), respectively. LA diameter (p<0.001) and LAA maximal area (p=0.01) showed to be independent predictors of LV size. LV thrombus was detected in 13 (13.7%) patients, while LAA thrombus in 46 (48.4%) patients of our study population.</AbstractText>In conclusion, dilated LV size is associated with enlarged LA and LAA size. On the other hand, dilation of LV, LA and LAA is related to high prevalence of left chamber cardiac thrombi.</AbstractText> |
13,414 | Racial differences in the incidence of and risk factors for atrial fibrillation in older adults: the cardiovascular health study. | This study examined whether different associations between risk factors and atrial fibrillation (AF) according to race could explain the lower incidence of AF in blacks. Baseline risk factor information was obtained from interviews, clinical examinations, and echocardiography in 4,774 white and 911 black Cardiovascular Health Study participants aged 65 and older without a history of AF at baseline in 1989/90 or 1992/93. Incident AF was determined according to hospital discharge diagnosis or annual study electrocardiogram. Cox regression was used to assess associations between risk factors and race and incident AF. During a mean 11.2 years of follow-up, 1,403 whites and 182 blacks had incident AF. Associations between all examined risk factors were similar in both races, except left ventricular posterior wall thickness, which was more strongly associated with AF in blacks (per 0.2 cm, blacks: hazard ratio (HR) = 1.72, 95% confidence interval (CI) = 1.44-2.06; whites: HR = 1.30, 95% CI = 1.18-1.43). Overall, the relative risk of AF was 25% lower in blacks than whites after adjustment for age and sex (HR = 0.75, 95% CI = 0.64-0.87) and 45% lower after adjustment for all considered risk factors (HR = 0.55, 95% CI = 0.35-0.88). Different associations of the considered risk factors and incident AF by race do not explain the lower incidence of AF in blacks. |
13,415 | Atrial activity extraction from single lead ECG recordings: evaluation of two novel methods. | Two different methods for extracting atrial activity (AA) signal from single lead electrocardiogram (ECG) of atrial fibrillation were proposed. The first one is a weighted average beat subtraction (WABS) method. Coefficients of QRS complexes used for constructing QRS template were obtained by minimizing mean square error. The second method is based on maximum likelihood estimation (MLE). Probability density functions of AA signal and ventricular activity (VA) signals were estimated using generalized Gaussian model. Then AA signal was extracted by maximizing likelihood function. Simulated signal and clinical ECG were used to evaluate the performance of ABS, WABS and MLE-based algorithm. In comparison with ABS, WABS and MLE-based algorithm reduced normal mean square error by 23.5% and 20.2%, respectively. |
13,416 | Plasma fibulin-1 is linked to restrictive filling of the left ventricle and to mortality in patients with aortic valve stenosis. | Plasma fibulin-1 levels have been associated with N-terminal pro-B-type natriuretic peptide levels and left atrial size and shown to be predictive of mortality in patients with diabetes. The mechanisms behind these connections are not fully understood but are probably related to its roles as an extracellular matrix protein in cardiovascular tissues.</AbstractText>One hundred twenty-five patients with severe aortic stenosis who were scheduled for aortic valve replacement (AVR) were evaluated with preoperative echocardiography and their plasma fibulin-1 levels were determined with ELISA. The cohort was followed for a median of 4 years after AVR. Increased restrictive left ventricular (LV) filling pattern was observed with increased plasma fibulin-1 levels (2% versus 29% versus 24% in low, middle, and high plasma fibulin-1 tertile groups, P=0.004). Likewise, reduced longitudinal systolic LV function (6.6 ± 1.1 versus 6.1 ± 1.3 versus 5.7 ± 1.5 cm/s, P=0.05) and increased LV filling pressures was systolic velocity of the mitral annulus observed with increasing plasma fibulin-1 concentrations (ratio of early transmitral flow velocity to early diastolic flow velocity of the mitral annulus 13 ± 4 versus 15 ± 5 versus 16 ± 6 in the fibulin-1 tertile groups, P=0.04).</AbstractText>In patients with symptomatic severe aortic stenosis undergoing AVR, plasma fibulin-1 is associated with restrictive filling of the LV, decreased longitudinal systolic function of the LV, and increased LV filling pressures.</AbstractText>URL: http://www.clinicaltrial.gov with Identifier: NCT00294775.</AbstractText> |
13,417 | H(2) gas improves functional outcome after cardiac arrest to an extent comparable to therapeutic hypothermia in a rat model. | All clinical and biological manifestations related to postcardiac arrest (CA) syndrome are attributed to ischemia-reperfusion injury in various organs including brain and heart. Molecular hydrogen (H(2)) has potential as a novel antioxidant. This study tested the hypothesis that inhalation of H(2) gas starting at the beginning of cardiopulmonary resuscitation (CPR) could improve the outcome of CA.</AbstractText>Ventricular fibrillation was induced by transcutaneous electrical epicardial stimulation in rats. After 5 minutes of the subsequent CA, rats were randomly assigned to 1 of 4 experimental groups at the beginning of CPR: mechanical ventilation (MV) with 2% N(2) and 98% O(2) under normothermia (37°C), the control group; MV with 2% H(2) and 98% O(2) under normothermia; MV with 2% N(2) and 98% O(2) under therapeutic hypothermia (TH), 33°C; and MV with 2% H(2) and 98% O(2) under TH. Mixed gas inhalation and TH continued until 2 hours after the return of spontaneous circulation (ROSC). H(2) gas inhalation yielded better improvement in survival and neurological deficit score (NDS) after ROSC to an extent comparable to TH. H(2) gas inhalation, but not TH, prevented a rise in left ventricular end-diastolic pressure and increase in serum IL-6 level after ROSC. The salutary impact of H(2) gas was at least partially attributed to the radical-scavenging effects of H(2) gas, because both 8-OHdG- and 4-HNE-positive cardiomyocytes were markedly suppressed by H(2) gas inhalation after ROSC.</AbstractText>Inhalation of H(2) gas is a favorable strategy to mitigate mortality and functional outcome of post-CA syndrome in a rat model, either alone or in combination with TH.</AbstractText> |
13,418 | Premature cardiac contractions and risk of incident ischemic stroke. | The etiologies of ischemic stroke remain undetermined in 15% to 40% of patients. Apart from atrial fibrillation, other arrhythmias are less well-characterized as risk factors. Premature cardiac contractions are known to confer long-term cardiovascular risks, like myocardial infarction. Ischemic stroke as cardiovascular risk outcome remains a topic of interest. We examined the prospective relationships in the Atherosclerosis Risk in Communities (ARIC) study, to determine whether premature atrial (PAC) or ventricular (PVC) contractions are associated with increased risk for incident ischemic stroke.</AbstractText>We analyzed 14 493 baseline stroke-free middle-aged individuals in the ARIC public-use data. The presence of PAC or PVC at baseline was assessed from 2-minute electrocardiogram. A physician-panel confirmed and classified all stroke cases. Average follow-up time was 13 years. Proportional hazards models assessed associations between premature contractions and incident stroke. PACs and PVCs were identified in 717 (4.9%) and 793 (5.5%) participants, respectively. In all, 509(3.5%) participants developed ischemic stroke. The hazard ratio (HR) (95% confidence interval [CI]) associated with PVC was 1.77 (1.30, 2.41), attenuated to 1.25 (0.91, 1.71) after adjusting for baseline stroke risk factors. The interaction between PVC and baseline hypertension was marginally significant (P=0.08). Among normotensives, having PVCs was associated with nearly 2-fold increase in the rate of incident ischemic stroke (HR 1.69; 95% CI 1.02, 2.78), adjusting for stroke risk factors. The adjusted risk of ischemic stroke associated with PACs was 1.30 (95% CI 0.92, 1.83).</AbstractText>Presence of PVCs may indicate an increased risk of ischemic stroke, especially in normotensives. This risk approximates risk of stroke from being black, male, or obese in normotensives from this cohort.</AbstractText> |
13,419 | Hands-on defibrillation has the potential to improve the quality of cardiopulmonary resuscitation and is safe for rescuers-a preclinical study. | Recently, it has been demonstrated that rescuers could safely provide a low, static downward force in direct contact with patients during elective cardioversion. The purpose of our experimental study was to investigate whether shock delivery during uninterrupted chest compressions may have an impact on cardiopulmonary resuscitation (CPR) quality and can be safely performed in a realistic animal model of CPR.</AbstractText>Twenty anesthetized swine were subjected to 7 minutes of ventricular fibrillation followed by CPR according to the 2010 American Heart Association Guidelines. Pregelled self-adhesive defibrillation electrodes were attached onto the torso in the ventrodorsal direction and connected to a biphasic defibrillator. Animals were randomized either to (1) hands-on defibrillation, where rescuers wore 2 pairs of polyethylene gloves and shocks were delivered during ongoing chest compressions, or (2) hands-off defibrillation, where hands were taken off during defibrillation. CPR was successful in 9 out of 10 animals in the hands-on group (versus 8 out of 10 animals in the hands-off group; not significant). In the hands-on group, chest compressions were interrupted for 0.8% [0.6%; 1.4%] of the total CPR time (versus 8.2% [4.2%; 9.0%]; P=0.0003), and coronary perfusion pressure was earlier restored to its pre-interruption level (P=0.0205). Also, rescuers neither sensed any kind of electric stimulus nor did Holter ECG reveal any serious cardiac arrhythmia.</AbstractText>Hands-on defibrillation may improve CPR quality and could be safely performed during uninterrupted chest compressions in our standardized porcine model.</AbstractText> |
13,420 | Right ventricular function and survival following cardiac resynchronisation therapy. | Right ventricular (RV) function is an important prognostic marker in heart failure. However, its impact on all-cause mortality following cardiac resynchronisation therapy (CRT) independent of confounding factors has not been evaluated. Furthermore, evidence concerning the effect of CRT on RV function is limited. The study's aims were to: (1) assess the prognostic importance of RV function among CRT recipients, and (2) characterise RV functional change following CRT and its determinants.</AbstractText>Retrospective observational study.</AbstractText>Single tertiary centre.</AbstractText>A total of 848 CRT recipients (median age 65 years, 78% male, 60% ischaemic) underwent echocardiography before and 6 months after CRT. RV function was evaluated using tricuspid annular plane systolic excursion (TAPSE), with a ≤14 mm threshold indicating severe RV impairment. The primary endpoint was long-term all-cause mortality.</AbstractText>Significant baseline RV dysfunction was observed in 286 (34%) individuals. After a median 44 months, 288 deaths occurred. RV impairment was associated with a greater incidence of all-cause mortality (log-rank p<0.001). Independent predictors of this endpoint were functional class, ischaemic aetiology, diabetes, atrial fibrillation, renal dysfunction, bigger left ventricular (LV) end-systolic volume, less LV dyssynchrony and reduced TAPSE. Importantly, TAPSE added prognostic value to these recognised prognostic parameters (likelihood-ratio test p<0.001). Furthermore, improvement in RV function after CRT was independent of the improvement in LV systolic function but significantly associated with the improvement in LV diastolic function. Importantly, a favourable RV functional response to CRT was associated with superior survival.</AbstractText>RV function is an independent predictor of long-term outcome following CRT.</AbstractText> |
13,421 | Prompt institution of percutaneous cardiopulmonary support managed perioperative refractory vascular spasm after isolated coronary artery bypass grafting surgery. | A 51-year-old Japanese male underwent on-pump coronary artery bypass grafting surgery. After weaning from cardiopulmonary bypass (348 min), sudden bradycardia and hypotension occurred, followed by ventricular fibrillation. Although defibrillation and infusion of catecholamine restored sinus rhythm, transesophageal echocardiography demonstrated severely reduced contraction of both ventricles, and perioperative vascular spasm was suspected. As vascular spasm was refractory to medications, percutaneous cardiopulmonary support (PCPS) system was quickly instituted under cardiac massage. Coronary angiography revealed vascular spasm of not only the native coronary arteries but also the implanted left internal thoracic artery. After 3 days of full hemodynamic assist, PCPS was withdrawn with no obvious abnormalities in regional wall motion by transesophageal echocardiography. The patient was extubated on postoperative day 6 with no impaired brain function. In this case, the immediate diagnosis of refractory vascular spasm by transesophageal echocardiography and full cardiocirculatory assistance by PCPS helped to save the life of the patient. |
13,422 | Induction of chagasic-like arrhythmias in the isolated beating hearts of healthy rats perfused with Trypanosoma cruzi-conditioned medium. | Chagas' myocardiopathy, caused by the intracellular protozoan Trypanosoma cruzi, is characterized by microvascular alterations, heart failure and arrhythmias. Ischemia and arrythmogenesis have been attributed to proteins shed by the parasite, although this has not been fully demonstrated. The aim of the present investigation was to study the effect of substances shed by T. cruzi on ischemia/reperfusion-induced arrhythmias. We performed a triple ischemia-reperfusion (I/R) protocol whereby the isolated beating rat hearts were perfused with either Vero-control or Vero T. cruzi-infected conditioned medium during the different stages of ischemia and subsequently reperfused with Tyrode's solution. ECG and heart rate were recorded during the entire experiment. We observed that triple I/R-induced bradycardia was associated with the generation of auricular-ventricular blockade during ischemia and non-sustained nodal and ventricular tachycardia during reperfusion. Interestingly, perfusion with Vero-infected medium produced a delay in the reperfusion-induced recovery of heart rate, increased the frequency of tachycardic events and induced ventricular fibrillation. These results suggest that the presence of parasite-shed substances in conditioned media enhances the arrhythmogenic effects that occur during the I/R protocol. |
13,423 | A comparison of etanercept vs. infliximab for the treatment of post-arrest myocardial dysfunction in a swine model of ventricular fibrillation. | To compare the effects of two TNF-α antagonists, etanercept and infliximab, on post-cardiac arrest hemodynamics and global left ventricular function (LV) in a swine model following ventricular fibrillation (VF).</AbstractText>Domestic swine (n=30) were placed under general anesthesia and instrumented before VF was induced electrically. After 7 min of VF, standard ACLS resuscitation was performed. Animals achieving return of spontaneous circulation (ROSC) were randomized to immediately receive infliximab (5 mg/kg, n=10) or etanercept (0.3 mg/kg [4 mg/m(2)], n=10) or vehicle (250 mL normal saline [NS], n=10) and LV function and hemodynamics were monitored for 3 h.</AbstractText>Following ROSC, mean arterial pressure (MAP), stroke work (SW), and LV dP/dt fell from pre-arrest values in all groups. However, at the 30 min nadir, infliximab-treated animals had higher MAP than either the NS group (difference 14.4 mm Hg, 95% confidence interval [CI] 4.2-24.7) or the etanercept group (19.2 mm Hg, 95% CI 9.0-29.5), higher SW than the NS group (10.3 gm-m, 95% CI 5.1-15.5) or the etanercept group (8.9 gm-m, 95% CI 4.0-14.4) and greater LV dP/dt than the NS group (282.9 mm Hg/s, 95% CI 169.6-386.1 higher with infliximab) or the etanercep group (228.9 mm Hg/s, 95% CI 115.6-342.2 higher with infliximab).</AbstractText>Only infliximab demonstrated a beneficial effect on post cardiac arrest hemodynamics and LV function in this swine model. Etanercept was no better in this regard than saline.</AbstractText>Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,424 | Initial experience with a novel percutaneous left atrial appendage exclusion device in patients with atrial fibrillation, increased stroke risk, and contraindications to anticoagulation. | Atrial fibrillation (AF) increases by fivefold a patient's risk for thromboembolic stroke. The main source of emboli in AF is the left atrial appendage (LAA). Therefore, LAA closure could reduce the risk for thromboembolic events in AF. The investigators report the first United States experience with a novel percutaneous LAA closure device, the Lariat snare device, and its outcomes in 21 patients with AF, CHADS2 scores ≥2, and contraindications to anticoagulation. The LAA was closed with a snare containing suture from within the pericardial space. The intraoperative success of the procedure was confirmed by left atrial angiography and transesophageal echocardiographic color Doppler flow. The effectiveness of the procedure was evaluated by follow-up transesophageal echocardiography. The incidence of periprocedural and short-term complications was assessed by reviewing medical records. Twenty patients (100%) had successful LAA exclusion that was preserved at 96 ± 77 days. No patient had a stroke during an average of 352 ± 143 days of follow-up. One patient had right ventricular perforation and tamponade that required surgical exploration and repair. Two patients required prolonged hospitalization: 1 because of pericardial effusion that required repeat pericardiocentesis and 1 because of noncardiac co-morbidities. Three patients developed pericarditis <1 month after the procedure, of whom 1 had associated pericardial effusion that required drainage. In conclusion, percutaneous LAA exclusion can be achieved successfully and with an acceptable incidence of periprocedural and short-term complications. Further studies are needed to determine whether LAA exclusion lowers the long-term risk for thromboembolic events in patients with AF and contraindications to anticoagulation. |
13,425 | Right ventricular function relates to functional capacity in men with atrial fibrillation and preserved left ventricular ejection fraction. | While left ventricular (LV) diastolic function (E/e') is related to functional capacity in patients with atrial fibrillation (AF), the underlying mechanism is unclear. Right ventricular (RV) function is related to prognosis in various diseases, however, its relationship with LV diastolic function is not well-studied. We sought to examine the reliability of echocardiographic indices of RV function in AF, the relationship between LV diastolic function and RV function, and the relationship between RV function and 6MWT distance in ambulatory patients with AF.</AbstractText>We designed a retrospective study evaluating 52 veterans with AF and preserved LV ejection fraction (LVEF) who underwent echocardiography and 6MWT at scheduled visits throughout 1 year. We performed pairwise correlation to evaluate reproducibility of echocardiographic indices of RV function measured 1 week apart. Multiple regression was used to assess the association of indices of RV function to LV diastolic function and functional capacity.</AbstractText>Most RV function indices had good to excellent correlation between 2 visits 1 week apart (coefficient 0.50-0.81) with test-retest variations of <6%, except for tricuspid annular plane systolic excursion (TAPSE), which had a significant variation in 9%. TAPSE, RV S' and RV e' were significantly related to LV diastolic function after adjusting for RV systolic pressure. After further adjustment for comorbidities, only RV S' and RV e' remained significantly related to 6MWT.</AbstractText>RV tissue Doppler measurements (S' and e') had good reproducibility and were independently related to LV diastolic function and 6MWT in men with AF and preserved LVEF.</AbstractText>Published 2013. This article is a U.S. Government work and is in the public domain in the USA.</CopyrightInformation> |
13,426 | Electrophysiological characterization and antiarrhythmic efficacy of the mixed potassium channel-blocking antiarrhythmic agent AZ13395438 in vitro and in vivo. | To examine the electrophysiological, hemodynamic, and antiarrhythmic effects of the novel antiarrhythmic agent AZ13395438.</AbstractText>The ion channel-blocking potency of AZ13395438 was assessed in Chinese hamster ovary cells stably expressing various human cardiac ion channels and in human atrial myocytes. The in vivo electrophysiological, hemodynamic, and antiarrhythmic effects of intravenously administered AZ13395438 were examined in anesthetized rabbits, in anesthetized naive dogs, and in dogs subjected to rapid atrial pacing (RAP) for 8 weeks. Pharmacokinetic/pharmacodynamic (PKPD) modeling was applied to predict the potency of AZ13395438 in increasing atrial and ventricular refractoriness.</AbstractText>AZ13395438 potently and predominantly blocked the atrial repolarizing potassium currents I(Kur), I(Ach), and I(to) in vitro. In vivo, AZ13395438 caused a concentration-dependent and selective increase in atrial refractoriness with no or small effects on ventricular refractoriness and repolarization and on hemodynamics in both rabbits and dogs. The PKPD modeling predicted unbound plasma concentrations of AZ13395438 of 0.20 ± 0.039, 0.38 ± 0.084, and 0.34 ± 0.057 µmol/L to increase the right atrial effective refractory period by 20 milliseconds in the rabbit and in the naive and the RAP dogs, respectively. In the RAP dog with atrial fibrillation (AF), AZ13395438 significantly increased AF cycle length and successfully converted AF to sinus rhythm in 12 of the 12 occasions at an unbound plasma concentration of 0.48 ± 0.076 µmol/L. During saline infusion, conversion was seen only in 4 of the 10 occasions (P = .003 vs AZ13395438). Furthermore, AZ13395438 reduced AF inducibility by burst pacing from 100% to 25% (P < .001).</AbstractText>AZ13395438 can be characterized as a mixed potassium ion channel-blocking agent that selectively prolongs atrial versus ventricular refractoriness and shows promising antiarrhythmic efficacy in a clinically relevant animal model of AF.</AbstractText> |
13,427 | Prognostic relevance of a non-invasive evaluation of right ventricular function and pulmonary artery pressure in patients with chronic heart failure. | To determine the prognostic relevance of the echocardiographic evaluation of pulmonary artery systolic pressure (PASP) and tricuspid annular plane systolic excursion (TAPSE) in patients with chronic heart failure (CHF). Pulmonary hypertension (PH) and right ventricular (RV) dysfunction have both been associated with poor prognosis in CHF.</AbstractText>A complete echocardiographic examination was performed in 658 outpatients with CHF and LVEF <45%. PASP was available in 544 (83%) patients, TAPSE in all patients, and E wave deceleration time (DT) in 643 (98%) patients. During a median follow-up period of 38 months, 125 patients died, 5 underwent urgent heart transplantation, and 5 had an appropriately detected and treated episode of ventricular fibrillation. At Cox survival analysis (composite endpoint was death, urgent heart transplantation, and ventricular fibrillation), patients with PASP ≥40 mmHg plus TAPSE ≤14 mm had a poorer prognosis than those with high PASP but preserved TAPSE; RV dysfunction associated with normal PASP did not carry additional risks. Similar results were obtained when patients were grouped on the basis of DT (restrictive vs. non restrictive) and TAPSE.</AbstractText>A simple echocardiographic evaluation of PASP and RV function with TAPSE may improve risk stratification in patients with CHF. Importantly, if PASP cannot be recorded at echocardiography, a restrictive DT, measurable in the vast majority of patients, may be coupled with TAPSE to stratify patients.</AbstractText> |
13,428 | [Radiofrequency ablation as acute treatment of ventricular arrhythmia]. | The role of radiofrequency ablation in the acute management of electrical storm is reviewed. Electrical storm is defined as three or more intervention-requiring episodes of ventricular fibrillation or ventricular tachycardia within 24 hours. The management of electrical storm includes antiarrhythmic therapy including beta blockers and correction of initiating causes as myocardial ischaemia and electrolyte disturbances. Radiofrequency ablation provides an alternative in the management of electrical storm in the case of failure of the medical therapy. |
13,429 | ZP123 reduces energy required for defibrillation by preventing connexin43 remodeling during prolonged ventricular fibrillation in swine. | In ventricular fibrillation, the uncoupling of gap junctions slows conduction velocity and increases action-potential dispersion, which slows and diminishes defibrillation. We studied how the peptide ZP123, a gap-junction enhancer, might lower defibrillation-energy requirements during ventricular fibrillation in live pigs. We randomly assigned 33 pigs into 3 groups: ZP123 (receiving a 1-µg/kg bolus and 10 µg/kg/hr of ZP123), control (receiving saline solution), and sham (undergoing a sham operation). After a 30-min administration of agents, ventricular fibrillation was induced and left untreated for 8 min. Biphasic defibrillation of 50 J was increased by 50-J increments as necessary. Defibrillation-energy requirements were defined as the lowest energy required to achieve defibrillation. Electrocardiographic values were obtained before and after the administration of agents. Western blot and immunofluorescence analyses were performed on ventricular myocardial samples. All but one pig survived. The ZP123 treatment did not alter electrocardiographic variables. In the ZP123 group, the average required defibrillation energy was lower than that in the control group (327.28±269.6 vs 610±192.64 J; P=0.015), and the cumulative percentage of successful defibrillation at upper energy levels was higher (P<0.05). Supraventricular rhythm occurred more often in the ZP123 group than in the control group (72.7% vs 50%, P=0.042). Western-blot and immunofluorescence results showed that ZP123 did not alter the total amount of connexin43 but did prevent its dephosphorylation. We conclude that ZP123 can reduce defibrillation-energy requirements by preventing connexin43 remodeling during prolonged ventricular fibrillation. |
13,430 | Hindlimb unloading results in increased predisposition to cardiac arrhythmias and alters left ventricular connexin 43 expression. | Hindlimb unloading (HU) is a well-established animal model of cardiovascular deconditioning. Previous data indicate that HU results in cardiac sympathovagal imbalance. It is well established that cardiac sympathovagal imbalance increases the risk for developing cardiac arrhythmias. The cardiac gap junction protein connexin 43 (Cx43) is predominately expressed in the left ventricle (LV) and ensures efficient cell-to-cell electrical coupling. In the current study we wanted to test the hypothesis that HU would result in increased predisposition to cardiac arrhythmias and alter the expression and/or phosphorylation of LV-Cx43. Electrocardiographic data using implantable telemetry were obtained over a 10- to 14-day HU or casted control (CC) condition and in response to a sympathetic stressor using isoproterenol administration and brief restraint. The arrhythmic burden was calculated using a modified scoring system to quantify spontaneous and provoked arrhythmias. In addition, Western blot analysis was used to measure LV-Cx43 expression in lysates probed with antibodies directed against the total and an unphosphorylated form of Cx43 in CC and HU rats. HU resulted in a significantly greater total arrhythmic burden during the sympathetic stressor with significantly more ventricular arrhythmias occurring. In addition, there was increased expression of total LV-Cx43 observed with no difference in the expression of unphosphorylated LV-Cx43. Specifically, the increased expression of LV-Cx43 was consistent with the phosphorylated form. These data taken together indicate that cardiovascular deconditioning produced through HU results in increased predisposition to cardiac arrhythmias and increased expression of phosphorylated LV-Cx43. |
13,431 | Altered platelet contents in survivors of early ischemic ventricular fibrillation: preliminary findings. | Early ischemic ventricular fibrillation (VF) in the setting of an acute myocardial infarction (AMI) due to thrombotic coronary occlusion remains a major health problem. Several animal studies have shown that platelet-dense granule contents released during thrombus formation can induce arrhythmias. We hypothesize that the platelet release reaction is involved in the predisposition to early ischemic VF. A case-control study was performed in patients who survived VF during a first AMI ("cases," n = 26) and in patients with one previous AMI without arrhythmias ("controls," n = 24). All patients were on aspirin 100 mg OD. Baseline platelet activation was assessed with flow cytometry. Response to activation was assessed with aggregometry, flow cytometry and PFA-100 analysis. Differences in platelet contents and content release were assessed by labeling platelet-dense granules with mepacrine and by measuring serotonin and ADP/ATP content. Patient and infarct characteristics and baseline platelet function tests were similar between groups. The mean time from event was 4.9 (±3.2) years among cases and 4.7 (±2.7) years among controls. Dense granule release was similar in cases versus controls. Platelet serotonin content in cases was higher than in controls (611 ± 118 ng/10E(9) platelets vs. 536 ± 141 ng/10(9), p = 0.048). Even years after the event, elevations in the platelet dense granule contents between VF survivors and controls may be detected. These preliminary findings shed new light on the pathophysiological mechanisms underlying ischemic VF, as platelet-dense granules may contain mediators of early ischemic VF risk. |
13,432 | Cardiac arrhythmias in recently diagnosed hypertensive patients at first presentation: an electrocardiographic-based study. | Various forms of cardiac arrhythmias have been documented in hypertensive subjects, and hypertension is an important risk factor for the development of atrial and ventricular arrhythmias and sudden death. Electrocardiography at rest easily documents significant arrhythmias in patients, and this study was carried out to determine the types and frequency of arrhythmias in hypertensive subjects at first presentation in the Hypertension Clinics of the University of Nigeria Teaching Hospital (UNTH) Enugu, Nigeria. The study was hospitalbased and retrospective in nature. The resting 12lead ECG reports of 346 consecutive hypertensive subjects seen at the Hypertension clinics of the UNTH Enugu over a 14 month period were retrieved from the case files and studied. Other information obtained from the case files included the age and gender of the subjects. The mean age of the subjects was 57.3 years. Ninety-five of the subjects had arrhythmias representing 27% of the study population, out of which fifty-five were males (57.9%) and forty were females (42.1%). However 26.9% of all the male subjects had arrhythmias while 28.2% of all the females had arrhythmias. Multiple ventricular ectopics, sinus tachycardia, sinus bradycardia and atrial fibrillation were the most prevalent arrhythmias. This study showed that a significant proportion of hypertensive subjects present initially with significant rhythm disturbances. |
13,433 | Pacemaker dependency after isolated aortic valve replacement: do conductance disorders recover over time? | Permanent pacemaker (PPM) implantation is required in 3-8% of all patients undergoing aortic valve replacement (AVR). Our aim was to evaluate long-term PPM dependency and recovery of atrioventricular (AV) conduction disorders during follow-up in these patients.</AbstractText>Since January 1997, a total of 2106 consecutive patients underwent isolated AVR at our institution. Of these, 138 patients (6.6%, 72 female, median age 71 (37-89) years) developed significant conduction disorders leading to PPM implantation postoperatively. Preoperative ECG showed normal sinus rhythm (n = 64), first degree AV block (n = 19), left bundle branch block (n = 13), right bundle branch block (n = 16), left anterior hemiblock (n = 14) and AV block with ventricular escape rhythm (n = 10). Atrial fibrillation was present in 23 patients. Pacemakers were implanted after a median of 7 (1-30) days following AVR. PPM dependency was analysed by ECG and pacemaker check during follow-up.</AbstractText>A total of 45 of 138 patients with postoperative PPM Implantation died during a mean follow-up time of 5.3 ± 4.7 years. A further 9 patients were lost to follow-up. Long-term survivals at 1, 5 and 10 years were 88%, 79% and 59%, respectively. Only 8 (10%) of 84 survivors were no longer pacemaker-dependent. The majority of patients (n = 66, 79%) required permanent ventricular stimulation, and the remaining 10 (13%) showed intermittent stimulation with a mean ventricular stimulation fraction of 73% (22-98%).</AbstractText>The majority of patients do not recover from AV conduction disorders after AVR. Since higher-grade AV blocks expose patients to a high risk of sudden death after surgery, we recommend early implantation of permanent pacemaker.</AbstractText> |
13,434 | Arrhythmogenesis in Brugada syndrome: impact and constrains of current concepts. | Brugada syndrome (BrS), an inherited arrhythmogenic disease first described in 1992, is characterized by ST segment elevations on the electrocardiogram in the right precordium and by a high occurrence of arrhythmias including the life-threatening ventricular tachycardia/fibrillation. Knowledge of the underlying mechanisms of formation of arrhythmogenic substrate in BrS is essential, namely for the risk stratification of BrS patients and their therapy which is still restrained almost exclusively to the implantation of cardioverter/defibrillator. In spite of many crucial findings in this field published within recent years, the final consistent view has not been established so far. Hence, BrS described 20 years ago remains an actual topic of both clinical and experimental studies. This review presents an overview of the current knowledge related to the pathogenesis of BrS arrhythmogenic substrate, namely of the genetic basis of BrS, functional consequences of mutations related to BrS, and arrhythmogenic mechanisms in BrS. |
13,435 | Predictive value of pre-procedural autoantibodies against M2-muscarinic acetylcholine receptor for recurrence of atrial fibrillation one year after radiofrequency catheter ablation. | Increasing evidences have suggested that autoantibodies against muscarinic-2 acetylcholine receptor (anti-M2-R) may play an important role in the development of atrial fibrillation (AF). Predictive value of pre-procedural anti-M2-R for the recurrence of AF after radiofrequency catheter ablation is still unclear.</AbstractText>Totally 76 AF patients with preserved left ventricular systolic function were prospectively enrolled and subjected to ablation after the detection of serum anti-M2-R by enzyme linked immunosorbent assay. These patients were given follow-up examination for one year after ablation. Risk estimation for the recurrence of AF was performed using the univariate and multivariate logistic regression.</AbstractText>In AF group, serum anti-M2-R was significantly higher than that in the control group in terms of frequency (40.8% versus 11.7%; p < 0.001) and titer (1:116 versus 1:29; p < 0.001). Compared with paroxysmal AF patients, persistent AF patients had higher frequency (57.6% versus 27.9%; p = 0.009) and titer (1:132 versus 1:94; p = 0.012) for autoantibodies. During one-year follow-up examination after ablation, the recurrence of AF was observed in 25 (32.9%) patients. Multivariate analysis showed that pre-procedural serum anti-M2-R was an independent predictor for the recurrence of AF at the time point of 12 months after ablation (odds ratio: 4.701; 95% confidence interval: 1.590-13.894; p = 0.005).</AbstractText>In AF patients, the frequency and titer of serum anti-M2-R were significantly higher than those in the control group with sinus rhythm. Pre-procedural serum anti-M2-R was an independent predictor for the recurrence of AF one year after radiofrequency catheter ablation.</AbstractText> |
13,436 | Flecainide acetate for the treatment of atrial and ventricular arrhythmias. | Flecainide is a class Ic antiarrhythmic agent available in Europe since 1982. The clinical development program of flecainide provided good data on its antiarrhythmic effect for the prevention of ventricular and supraventricular arrhythmias. The Cardiac Arrhythmia Suppression Trial (CAST), conducted to test whether the arrhythmia suppression translates into prevention of sudden death, assessed the impact of flecainide and encainide therapy in patients with frequent ventricular ectopics and reduced left ventricular function who had survived an infarction. In that population, flecainide and encainide increased mortality. Consequently, sodium channel blockers are now rarely used to prevent sudden death and are not recommended in patients with heart failure. Current European and North American guidelines recommend the use of flecainide in carefully selected patients with atrial fibrillation (AF) and no documented structural heart disease.</AbstractText>The aim of this review is to evaluate the available data on efficacy and safety of flecainide in all the spectrum of its indications including cardioversion of recent-onset AF, sinus rhythm maintenance in paroxysmal AF and management of ventricular tachyarrhythmias.</AbstractText>In the setting of AF and in carefully selected patients without structural heart disease, flecainide has shown a good efficacy and safety for both cardioversion and sinus rhythm maintenance.</AbstractText> |
13,437 | Late sodium current inhibition in acquired and inherited ventricular (dys)function and arrhythmias. | The late sodium current has been increasingly recognized for its mechanistic role in various cardiovascular pathologies, including angina pectoris, myocardial ischemia, atrial fibrillation, heart failure and congenital long QT syndrome. Although relatively small in magnitude, the late sodium current (I(NaL)) represents a functionally relevant contributor to cardiomyocyte (electro)physiology. Many aspects of I(NaL) itself are as yet still unresolved, including its distribution and function in different cell types throughout the heart, and its regulation by sodium channel accessory proteins and intracellular signalling pathways. Its complexity is further increased by a close interrelationship with the peak sodium current and other ion currents, hindering the development of inhibitors with selective and specific properties. Thus, increased knowledge of the intricacies of the complex nature of I(NaL) during distinct cardiovascular conditions and its potential as a pharmacological target is essential. Here, we provide an overview of the functional and electrophysiological effects of late sodium current inhibition on the level of the ventricular myocyte, and its potential cardioprotective and anti-arrhythmic efficacy in the setting of acquired and inherited ventricular dysfunction and arrhythmias. |
13,438 | Mechanisms responsible for beneficial and adverse effects of rosiglitazone in a rat model of acute cardiac ischaemia-reperfusion. | Despite debate regarding its cardioprotective and pro-arrhythmic effects, the precise mechanisms of action of rosiglitazone on the heart are still unclear. We determined the mechanistic effects of rosiglitazone on cardiac function, arrhythmias and infarct size during cardiac ischaemia-reperfusion. Twenty-six rats were used. In each rat, either rosiglitazone or saline solution was administered intravenously prior to a 30 min left anterior descending coronary artery ligation and a 120 min reperfusion. Cardiac function, infarct size, myocardial levels of connexin43, Bax/Bcl-2, cytochrome c, caspase-3, caspase-8, Akt, tumour necrosis factor-α and interleukin-4 and cardiac mitochondrial function were determined. Isolated cardiomyocytes were used for studying intracellular calcium. Rosiglitazone did not alter cardiac function during the ischaemia-reperfusion periods, but increased the arrhythmia score and mortality rate, decreased the time to onset of ventricular fibrillation and prolonged the Ca2+ decay rate, in comparison to the saline-injected group (P<0.05). However, the infarct size in the rosiglitazone-injected group was reduced (P<0.05). Rosiglitazone decreased the levels of connexin43 phosphorylation, active caspase-8 and tumour necrosis factor-α, but increased the level of procaspase-3. However, levels of Bax/Bcl-2, cytochrome c, Akt and interleukin-4 and the cardiac mitochondrial function were not different between the two groups. Rosiglitazone simultaneously exerted both beneficial and adverse cardiac effects in the heart exposed to ischaemia-reperfusion. Although it decreased the infarct size via the extrinsic anti-apoptotic pathway and anti-inflammatory effects, rosiglitazone facilitated a fatal arrhythmia by decreasing connexin43 phosphorylation and prolonging the Ca2+ decay rate in ischaemia-reperfusion. The higher mortality rate in the rosiglitazone-injected group suggests that its undesirable effect was more pronounced than its benefit on infarct size reduction. |
13,439 | The mechanical uncoupler blebbistatin is associated with significant electrophysiological effects in the isolated rabbit heart. | Blebbistatin (BS) is a recently discovered inhibitor of the myosin II isoform and has been adopted as the mechanical uncoupler of choice for optical mapping, because previous studies suggest that BS has no significant cardiac electrophysiological effects in a number of species. The aim of this study was to determine whether BS affects cardiac electrophysiology in isolated New Zealand White rabbit hearts. Langendorff-perfused hearts (n=39) in constant-flow mode had left ventricular monophasic action potential duration (MAPD) measured at apical and basal regions during constant pacing (300 ms cycle length). Standard action potential duration restitution was obtained using the single extrastimulus method with measurement of the maximal restitution slope. Ventricular fibrillation threshold was measured as the minimal current inducing sustained ventricular fibrillation with burst pacing (30 stimuli, at 30 ms intervals). Optical action potentials were recorded using the voltage-sensitive dye di-4-ANEPPS. Measurements were taken at baseline and after 60 min perfusion with BS (5 μm). Blebbistatin significantly prolonged left ventricular apical (mean±SEM; from 129.9±2.9 to 170.7±4.1 ms, P<0.001, n=8) and basal MAPD (from 135.0±2.3 to 163.3±5.6 ms, P<0.001) and effective refractory period (from 141.3±4.8 to 175.6±3.7 ms, P<0.001) whilst increasing the maximal slope of restitution (apex, from 0.79±0.09 to 1.57±0.16, P<0.001; and base, from 0.71±0.06 to 1.44±0.24, P<0.001) and ventricular fibrillation threshold (from 5.3±1.1 to 17.0±2.9 mA, P<0.001). In other hearts, blebbistatin significantly prolonged optically recorded action potentials (from 136.5±6.3 to 173.0±7.9 ms, P<0.05, n=4). In control experiments, the increase of MAPD with blebbistatin was present whether the hearts were perfused in constant-pressure mode (n=5) or in unloaded conditions (n=5). These data show that blebbistatin significantly affects cardiac electrophysiology. Its use in optical mapping studies should be treated with caution. |
13,440 | Prognosis of patients with atrial fibrillation undergoing percutaneous coronary intervention receiving drug eluting stents. | Atrial fibrillation (AF) is increasingly prevalent in elderly patients and adversely affects clinical outcomes after coronary artery bypass grafting, non-cardiac surgery or myocardial infarction. Aim of the present analysis was to investigate the prognostic impact of AF in patients undergoing drug eluting stent (DES) implantation during a 1-year follow-up.</AbstractText>5,772 consecutive patients undergoing percutaneous coronary intervention were enrolled into the German Drug Eluting Stent Registry (DES.DE) and were followed for 12 months. Of these 455 had AF and 5,317 in sinus rhythm served as controls. Univariate and multivariate logistic regression analyses were used to determine the risk of major adverse cardiac and cerebrovascular events (MACCE) and bleeding complications.</AbstractText>Patients with AF were older (71.3 ± 7.6 vs. 64.7 ± 10.5 years) and had a higher prevalence of diabetes, hypertension, renal insufficiency as well as more prior bypass surgery, stroke and peripheral arterial disease. Cardiogenic shock (2.9 vs. 1.4 %; p < 0.05), left ventricular ejection fraction ≤40 % (21.0 vs. 11.4 %; p < 0.0001) and triple vessel disease (44.4 vs. 37.9 %; p < 0.01) were more frequent in patients with AF than in controls. MACCE (OR 2.08, 95 % CI 1.56-2.77), total mortality (OR 3.27, 95 % CI 2.32-4.62) and non-fatal stroke (OR 2.03, 95 % CI 1.03-4.00) as well as bleeding complications (OR 1.88, 95 % CI 1.13-3.12) during the 1-year follow-up were more frequent in patients with AF (univariate analysis). In multivariate analyses adjusting for covariates determined to be relevant at baseline, the risk for total mortality remained elevated (OR 1.63, 95 % CI 1.05-2.52).</AbstractText>AF is an important predictor of long-term mortality in patients undergoing DES implantation.</AbstractText> |
13,441 | External validation of a novel transthoracic echocardiographic tool in predicting left atrial appendage thrombus formation in patients with nonvalvular atrial fibrillation. | A recent study demonstrated that in patients with nonvalvular atrial fibrillation (AF), a ratio of left ventricular ejection fraction (LVEF) to the left atrial volume index (LAVI) of <1.5 has 100% sensitivity for detecting left atrial appendage (LAA) thrombus. We sought to validate this prediction tool in an external cohort.</AbstractText>We conducted a cohort study of consecutive AF patients who underwent transoesophageal echocardiogram (TEE) to 'rule-out' LAA thrombus and had a prior transthoracic echocardiogram (TTE). The LAVI and LVEF were measured to calculate LVEF/LAVI ratio. The sensitivity and specificity of LVEF/LAVI <1.5 were calculated.</AbstractText>Among 215 subjects, 19 (8.8%) had LAA thrombus and also had a higher mean CHADS2 score (2.5 vs. 1.9, P = 0.04), lower mean LVEF (24 vs. 44%, P < 0.001), higher mean LAVI (44 mL/m2 vs. 30 mL/m2, P < 0.001), and higher prevalence of cardiac failure (79 vs. 52%, P = 0.02). The LVEF and LAVI were found to be independent predictors of LAA thrombus (P < 0.05). The LVEF/LAVI ratio diagnosed LAA thrombus with an area under the curve = 0.83 by the receiver operator characteristics curve analysis (P < 0.001). All 19 (100%) subjects with LAA thrombus had LVEF/LAVI <1.5 vs. 87 (44%) among those without LAA thrombus (P < 0.001). The sensitivity and specificity of LVEF/LAVI <1.5 were 100 and 55.6%, respectively.</AbstractText>This investigation validates a simple TTE prediction rule to exclude the diagnosis of LAA thrombus, which may obviate the need for pre-cardioversion TEE in selected patients with nonvalvular AF.</AbstractText> |
13,442 | Early repolarization pattern and risk for arrhythmia death: a meta-analysis. | A meta-analysis was performed to determine the risk and incidence rate of arrhythmia death, cardiac death, and all-cause death in the general population with the early repolarization pattern (ERP).</AbstractText>The ERP has recently been associated with vulnerability to ventricular fibrillation in case-control studies. However, the prognostic significance of the ERP in the general population is controversial.</AbstractText>Relevant studies published through July 31, 2012, were searched and identified in the MEDLINE and Embase databases. Studies that reported risk ratio estimates with 95% confidence intervals (CIs) for the associations of interest were included. Data were extracted, and summary estimates of association were obtained using a random-effects model.</AbstractText>Of the 9 studies included, 3 studies reported on arrhythmia death (31,981 subjects, 1,108 incident cases during 726,741 person-years of follow-up), 6 studies reported on cardiac death (126,583 subjects, 10,010 incident cases during 2,054,674 person-years of follow-up), and 6 studies reported on all-cause death (112,443 subjects, 22,165 incident cases during 2,089,535 person-years of follow-up). The risk ratios of the ERP were 1.70 (95% CI: 1.19 to 2.42; p = 0.003) for arrhythmia death, 0.78 (95% CI: 0.27 to 2.25; p = 0.63) for cardiac death, and 1.06 (95% CI: 0.87 to 1.28; p = 0.57) for all-cause death. The estimated absolute risk differences of subjects with the ERP were 70 cases of arrhythmia death per 100,000 subjects per year. J-point elevation ≥ 0.1 mV in the inferior leads and notching configuration had an increased risk for arrhythmia death in subgroup studies.</AbstractText>The ERP was associated with increased risk and a low to intermediate absolute incidence rate of arrhythmia death. Further study is needed to clarify which subgroups of subjects with the ERP are at higher risk for arrhythmia death.</AbstractText>Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,443 | Cerebral embolism due to atrial myopathy in a cardiac amyloidosis patient diagnosed by cardiac magnetic resonance imaging. | A 55-year-old woman was admitted with heart failure. On the third hospital day, she suddenly developed cerebral infarction. The resting 12-lead electrocardiography showed normal sinus rhythm, and atrial fibrillation or flutter were never detected on electrocardiographic monitoring throughout the whole hospital days. She had no other conventional risk factor for cerebral infarction. Transthoracic echocardiography showed left ventricular hypertrophy. Transesophageal echocardiogram revealed strong spontaneous echo contrast in the left atrium (LA), and the blood flow in the left atrial appendage was extremely decreased (22.3 cm/s). Late gadolinium enhancement in cardiac magnetic resonance (CMR) imaging showed global subendocardial hyperenhancement of the left ventricle and both atria. Endomyocardial biopsy specimen was positive for amyloid by Congo red staining. Marked amyloid infiltration to both atria might cause atrial dysfunction leading to thrombus formation in the LA. CMR is thought to be a useful noninvasive tool to detect atrial myopathy in cardiac amyloidosis patients. <<b>Learning objective:</b> In cardiac amyloidosis patients, late gadolinium enhancement on CMR in the atria might be an important sign, which would suggest atrial amyloid deposition with impaired atrial function. CMR is thought to be a useful noninvasive tool to detect even atrial myopathy in cardiac amyloidosis patients. Furthermore, we recommend to evaluate the atrial function using transesophageal echocardiography in these patients. If impaired atrial function was detected, despite with or without atrial fibrillation, they should receive anticoagulation therapy for preventing the thromboembolic event.>. |
13,444 | Plasma B-type natriuretic peptide level in patients with acute cerebral infarction according to infarction subtype and infarction volume. | Plasma B-type natriuretic peptide (BNP) is used as a diagnostic marker of cardiovascular diseases. BNP is secreted mainly from the myocardium and has been detected by immunoreactivity in brain and cerebral arteries. The aim of our study was to investigate plasma BNP in patients with acute cerebral infarction according to infarction subtype and infarction volume.</AbstractText>We studied 141 patients with acute cerebral infarction, classified as large artery atherosclerosis (LAA), cardioembolism (CE), or small vessel disease (SA) according to the Trial of Org 10172 in Acute Stroke Treatment classification. Plasma BNP level was measured in patients and 61 healthy controls. We analyzed various clinical and laboratory variables of patients according to plasma BNP level.</AbstractText>Compared to controls, the patients had higher plasma BNP (11.9 ± 11.7 pg/mL versus 124.6 ± 228.8 pg/mL, p <0.01). The highest quartile BNP group was associated with advanced age, female gender, current non-smoker, atrial fibrillation, heart failure, CE group, increased white blood cell counts, increased high sensitivity C-reactive protein, increased left atrium size, decreased left ventricular ejection fraction, increased initial National Institute of Health Stroke Scale, and increased infarction volume. According to multiple regression analysis, CE group, female gender, and infarction volume were independently associated with plasma BNP. Plasma BNP level showed statistically significant differences among LAA (n = 71), CE (n = 50), and SA (n = 20) groups (p <0.001), and the expression decreased in order of CE (253.8 ± 337.1 pg/mL), LAA (61.6 ± 78.8 pg/mL), and SA (25.3 ± 24.8 pg/mL). Increased plasma BNP correlated with increased infarction volume (r = 0.42, p <0.001).</AbstractText>Plasma BNP may be helpful for prediction of etiologic classification of acute cerebral infarction and infarction volume.</AbstractText> |
13,445 | Levosimendan in acute heart failure following primary percutaneous coronary intervention-treated acute ST-elevation myocardial infarction. Results from the LEAF trial: a randomized, placebo-controlled study. | The calcium sensitizer levosimendan may counteract stunning after reperfusion of ischaemic myocardium, but no randomized placebo-controlled trials exist regarding its use in PCI-treated ST-segment elevation infarction (STEMI). We evaluated the efficacy and safety of levosimendan in patients with a primary PCI-treated STEMI complicated by symptomatic heart failure (HF).</AbstractText>A total of 61 patients developing clinical signs of HF within 48 h after a primary PCI-treated STEMI (including cardiogenic shock) were randomized double-blind to a 25 h infusion of levosimendan or placebo. The primary endpoint was change in wall motion score index (WMSI) from baseline to day 5 measured by echocardiography. There was a significantly larger improvement in WMSI from baseline to day 5 in the levosimendan group compared with placebo (from 1.94 ± 0.20 to 1.66 ± 0.31 vs. 1.99 ± 0.22 to 1.83 ± 0.26, respectively, P = 0.031). There were significantly more episodes of hypotension during study drug infusion in the levosimendan group (67% vs. 36%, P = 0.029), but no significant difference in blood pressure at the end of infusion or in use of vasopressors. No significant between-group differences in changes in NT-proBNP levels, clinical composite score, frequency of atrial fibrillation or ventricular arrhythmia, infarct size at 6 weeks, or new clinical events up to 6 months were found. One and four patients died in the levosimendan and placebo group, respectively.</AbstractText>Levosimendan treatment improved contractility in post-ischaemic myocardium in patients with PCI-treated STEMI complicated by HF. The treatment was well tolerated, without any increase in arrhythmias.</AbstractText> |
13,446 | Pro- and anti-arrhythmic effects of anti-inflammatory drugs. | Inflammatory process is strongly associated with cardiac arrhythmia, either as a cause or a consequence. Antiinflammatory drugs are widely prescribed, and some of them have been associated with an increased cardiovascular risk. Then, the eventual pro- or anti-arrhythmic effect of these drugs is of high interest for clinical practice. This review summarizes pro- and anti-arrhythmic effects of anti-inflammatory drugs, based on the analysis of published clinical trials. Cardiac arrhythmias are divided into atrial fibrillation (AF) and ventricular arrhythmias. Based on the literature and on pathophysiology, post-operative AF and post-ablative AF are analyzed separately. After a brief overview of fundamental mechanisms of arrhythmia and their relationship to inflammation, we thought to examine corticosteroids, non-steroidal anti-inflammatory drugs (NSAIDs), and colchicine effects on cardiac arrhythmias. All anti-inflammatory drugs have demonstrated anti-arrhythmic properties in post operative AF. Apart from this specific condition, NSAIDs and corticosteroids increase the risk of AF. Regarding ventricular arrhythmias the effects of these drugs are not well established and would require further investigations. |
13,447 | Effects of acute administration of ethanol on experimental arrhythmia. | Many studies have shown that the relationship between alcohol consumption and most cardiovascular diseases is U-shaped, with nondrinkers and heavier drinkers having higher risks than moderate drinkers. However, the association between cardiac arrhythmias and acute alcohol consumption is not well understood. We set up several experimental arrhythmia animal models to examine the effects of acute administration of ethanol on arrhythmia. The results showed 0.4, 0.8 and 1.6 g/kg ethanol consumption obviously delayed the onset time of atrial fibrillation (AF) (P < 0.05 or P < 0.01) and increased the survival rates on acetylcholine-CaCl₂-induced AF in mice. Ethanol (0.4, 0.8 and 1.6 g/kg) consumption significantly delayed the onset time of ventricular tachycardia (VT), ventricular fibrillation (VF) and cardiac arrest (CA) (P < 0.01), and 0.4 and 0.8 g/kg ethanol consumption increased the survival rates on CaCl₂-induced arrhythmia in rats. Ethanol (0.4 g/kg) essentially increased the cumulative dosage of aconitine required to CA (P < 0.05), and 0.8 g/kg, 1.6 g/kg ethanol reduced the cumulative aconitine dosage to induce VT, VF and CA (P < 0.05 or P < 0.01) on aconitine-induced arrhythmia in rats. Ethanol (0.4, 0.8 and 1.6 g/kg) consumption remarkably increased the cumulative dosage of deslanoside to induce ventricualr premature contraction (P < 0.01) on deslanoside-induced arrhythmia in guinea pigs. Collectively, our results indicate that low concentrations of ethanol had anti-arrhythmic effect on experimental arrhythmia, and high concentrations of ethanol may aggravated the occurrence of experimental arrhythmia. |
13,448 | Atrial tachyarrhythmias and the Cox-maze procedure in congenital heart disease. | Atrial tachyarrhythmias, particularly atrial flutter and fibrillation, are commonly associated with congenital heart disease and are a major cause of morbidity and mortality. The Cox-maze procedure, introduced by Dr. James Cox in 1987, is effective at controlling atrial fibrillation in structurally normal hearts. Though the Cox-maze procedure has been used for atrial tachyarrhythmias in patients with congenital heart disease, few studies have looked at its effectiveness.</AbstractText>A retrospective chart review was performed on 24 patients with congenital heart disease who underwent the Cox-maze procedure at the Medical College of Wisconsin from 2004 through 2010.</AbstractText>Mean age at time of Cox-maze procedure for the cohort was 40.9 years (range, 14 to 66 years). The most common congenital heart diseases among the patients included tetralogy of Fallot (n = 8) and atrioventricular septal defect (n = 4). All patients had concomitant cardiac procedures with the most common being right ventricular outflow tract reconstruction (n = 10), tricuspid valve repair (n = 8), and atrial septal defect repair (n = 7). Prior to the Cox-maze procedure, arrhythmias consisted of atrial flutter or intratrial reentrant tachycardia (n = 19) and atrial fibrillation (n = 5). There were three early postoperative deaths and one late postoperative death. Follow-up was available for 19 of 21 (90%) survivors with a mean length to follow-up from Cox-maze procedure of 2.8 years (range, 0.14-5.7 years). At last follow-up, 14 (74%) of the survivors remained arrhythmia-free.</AbstractText>In patients with congenital heart disease and atrial tachyarrhythmias, the majority were rendered arrhythmia-free by the Cox-maze procedure.</AbstractText>© 2012 Wiley Periodicals, Inc.</CopyrightInformation> |
13,449 | Prognostic value of the E/e' ratio among octogenarians in Singapore. | This study sought to investigate the prognostic value of the medial E (early transmitral flow velocity) to e' (early diastolic mitral annulus velocity) ratio (E/e') using the standard cutoff value of 15 among octogenarians stratified according to left ventricular ejection fraction (LVEF), atrial fibrillation (AF) and diabetes.</AbstractText>We examined a consecutive, single-centre cohort of 1197 subjects (male = 39.3%, female = 60.6%) between 80 and 89 years old (mean ± SD = 82.9 ± 2.81) who underwent transthoracic echocardiography from January 2009 to January 2011. E/e' and LVEF were measured. These subjects were prospectively followed up for 29 months (mean ± SD = 12.8 ± 7.9). Primary endpoint was all-cause mortality.</AbstractText>In univariate analysis, patients with underlying AF (AF vs no AF, p<0.001), diabetes (diabetes vs no diabetes, p<0.001), cancer (cancer vs no cancer, p<0.001), LVEF <45% (≥45% vs <45%, p<0.001) or an E/e' ≥15 (≥15 vs <15, p<0.001) had a poorer prognosis. Gender had no significant effect on prognosis (p<0.08). In multivariate analysis, age, AF, diabetes, cancer, a LVEF <45% and E/e' ≥15 were significant, independent predictors of a poor prognosis.</AbstractText>E/e' is a predictor of mortality among octogenarians independently of LVEF, AF and diabetes.</AbstractText> |
13,450 | Successful resuscitation in a case of sudden cardiac arrest in an epileptic patient posted for spinal surgery. | A 17-year-old girl was posted for spinal surgery for traumatic spinal injury. The patient was a well-controlled epileptic with history of seizure since 8 years of her age. She was induced with thiopentone sodium and muscle relaxant atracurium was administered. Minutes after that, she had an episode of ventricular tachycardia, this converted to ventricular fibrillation despite of institution of cardiopulmonary resuscitation (CPR). CPR was continued for a prolonged period of 45 minutes and after 45 minutes, QRS complexes appeared and later sinus rhythm restored. Next 24 hours, she was kept on mechanical ventilation. Within 24 hours, Glasgow Coma Scale (GCS) improved and patient was conscious and extubated. We suggest that the neuromuscular blocking drug contributed to an anaphylactic reaction which might be the cause of cardiac arrest and highlight the importance of prolonged resuscitation and successful outcome in this scenario. |
13,451 | Serum troponin I as an indicator of myocarditis in lambs affected with foot and mouth disease. | Foot and mouth disease (FMD) is a highly contagious viral disease of cloven-hooved livestock and wildlife results to relatively high mortality in young animals. Despite the numerous reports of FMD-related death in neonates, there is little data available on various aspects of FMD in lambs. This report describes myocarditis associated with FMD in five, one week to three months old lambs. The lambs were depressed and afebrile and two of lambs showed foamy salivation associated with shallow ulcers in oral cavity. Electrocardiography (ECG) revealed sinus tachycardia, multifocal ventricular premature beats and ventricular fibrillation. Serum biochemistry showed high levels of troponin I concentration and CK and AST activity. In Pathology, there were multiple pale areas in the subepicardial and subendocardial muscles and; widespread degeneration and coagulative necrosis of myocardium. The serum troponin I assay and ECG can be used for diagnosis of myocarditis and prognosis of affected lambs during FMD outbreak. |
13,452 | Effects of hypothermia on the liver in a swine model of cardiopulmonary resuscitation. | The study aimed to explore the effects of hypothermia state induced by 4 ºC normal saline (NS) on liver biochemistry, enzymology and morphology after restoration of spontaneous circulation (ROSC) by cardiopulmonary resuscitation (CPR) in swine.</AbstractText>After 4 minutes of ventricular fibrillation (VF), standard CPR was carried out. Then the survivors were divided into two groups: low temperature group and normal temperature group. The low temperature (LT) group (n=5) received continuously 4 ºC NS at the speed of 1.33 mL/kg per minute for 22 minutes, then at the speed lowering to 10 mL/kg per hour. The normal temperature (NT) group (n=5) received NS with normal room temperature at the same speed of the LT group. Hemodynamic status and oxygen metabolism were monitored and the levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were measured in blood samples obtained at baseline and at 10 minutes, 2 hours and 4 hours after ROSC. At 24 hours after ROSC, the animals were killed and the liver was removed to determine the Na(+)-K(+)-ATPase and Ca(2+)-ATPase enzyme activities and histological changes under a light or electron microscope.</AbstractText>Core temperature was decreased in the LT group (P<0.05), while HR, MAP and CPP were not significantly decreased (P>0.05) compared with the NT group (P>0.05). The oxygen extraction ratio was lower in the LT group than in the NT group (P<0.05). The serum levels of ALT, AST and LDH increased in both groups but not significantly in the LT group. The enzyme activity of liver ATP was much higher in the LT group (Na(+)-K(+)-ATP enzyme: 8.64±3.32 U vs. 3.28±0.71 U; Ca(2+)-ATP enzyme: 10.92±2.12 U vs. 2.75±0.78 U, P<0.05). The LT group showed less cellular edema, inflammation and few damaged mitochondria as compared with the NT group.</AbstractText>These data suggested that infusing 4 ºC NS continuously after ROSC could quickly lower the core body temperature, while maintaining a stable hemodynamic state and balancing oxygen metabolism, which protect the liver in terms of biochemistry, enzymology and histology after CPR.</AbstractText> |
13,453 | Giant fibroelastoma of the aortic valve. | Fibroelastomas account for less than 10% of all cardiac tumours, representing the most common valvular and the second most common cardiac benign tumour, following myxomas. Fibroelastomas are histologically benign; they can result in life-threatening complications such as stroke, acute valvular dysfunction, embolism, ventricular fibrillation, and sudden death. Surgical resection should be offered to all patients who have symptoms and to asymptomatic patients who have pedunculated lesions or tumors larger than 1 cm in diameter. Valve-sparing excision produces good long-term results in most instances. We report our surgical experience of a giant fibroelastoma in the aortic valve. |
13,454 | Brugada pattern electrocardiogram unmasked with cocaine ingestion. | Cocaine is considered a leading cause of drug-related deaths. This is usually sudden, unwitnessed, and without prodromal features. It has been reported that in-hospital mortality is close to 2%. Cocaine has powerful central nervous system effects(1) and acute cocaine overdose has been associated with hyperthermia, agitation, paranoid ideation, status epilepticus, ventricular fibrillation, ventricular tachycardia, and myocardial infarction (MI). The mechanisms of cocaine-related death remain poorly understood. We report a patient who survived massive cocaine ingestion with psychomotor agitation and generalized seizures followed by asystolic cardiac arrest and transient Brugada pattern on electrocardiogram (ECG). |
13,455 | [Predictive value of cardiopulmonary exercise testing in various categories of patients with chronic heart value]. | To specify the prognostic value of parameters of cardiopulmonary exercise testing (CPET) in patients with chronic heart value (CHF) on optimal medical treatment depending on gender, age, left ventricular ejection fraction (LVEF), cardiac rhythm and achievement of target respiratory exchange ratio (RER) > or = 1.0.</AbstractText>111 patients (83 male, mean age 60.6 +/- 12.8 years) with CHF NYHA class I-III on optimal treatment were included in the study. One third had preserved EF, 27.9%--permanent atrial fibrillation (AFib). Average followup was 19.4 +/- 9.6 months. Prognostic value of CPET indices and Heart Failure Survival Score (HFSS) for cardiovascular mortality (CVM) and combined endpoint including CVM or CHF hospitalization were evaluated using logistic regression analysis.</AbstractText>CVM amounted 14.4%, combined endpoint was observed in 46.8% of patients. HFSS had the highest predictive value for CVM (in all subgroups of patients) and for combined endpoint (except patients with AFib). In men, patients younger than 65 years, with reduced LVEF and with Afib CVM was also related to ventilatory indices (VE/VCO2, ventilatory class and PetCO2 peak), and combined endpoint was related to VO2peak and its derivativatives. Only HFSS and VE/VCO2 had prognostic value for CVM in patients with AFib. Ventilatory parameters were associated with combined endpoint in all subgroups except Afib. Blood pressure response and heart rate recovery had prognostic significance only in patients with sinus rhythm. Target RER > or = 1.0 was achieved only in 40.5% patients. In patients with RER < 1.0 significant relationship between VO2 peak and combined endpoint was observed. CONCLUSIONS; Heart Failure Survival Score, VE/VCO2, ventilatory class and PetCO peak are the strongest predictors of cardiovascular mortality and heart failure hospitalizations in all subgroups of patients with CHF. CPET has the highest significance for men, age < 65 years, patients with LVEF < 45% and sinus rhythm. In these subgroups VO2 peak and Weber class have predictive value for decompensation of CHF whether RER > or = 1.0 or not. Blood pressure response and heart rate recovery have prognostic significance only in patients with sinus rhythm.</AbstractText> |
13,456 | [Possibilities myocardial biopsy in the diagnosis of myocarditis verification in patients with idiopathic arrhythmias].<Pagination><StartPage>21</StartPage><EndPage>30</EndPage><MedlinePgn>21-30</MedlinePgn></Pagination><Abstract><AbstractText Label="UNLABELLED">Aim of the study was to elucidate nosological nature of "idiopathic" arrhythmias by means of right ventricular endomyocardial biopsy (EMB) and to assess effect of etiotropic and pathogenetic treatment.</AbstractText><AbstractText Label="MATERIAL AND METHODS" NlmCategory="METHODS">We included into this study 19 patients (mean age 42.6 +/-11.3 years, 9 women) with atrial fibrillation (AF, n = 16), supraventricular (n = 10) and ventricular (n = 4) extrasystoles (SVE and VE), supraventricular (n = 2) and ventricular (n = 1) tachycardia (SVT and VT), left bundle branch block (LBBB, n = 2), atrioventricular block (n = 2) without structural changes of the heart. In addition to standard examination we performed the following tests: determination of IgG to herpes and Coxsackie B virus, polymerase chain reaction (PCR) for DNA detection of human herpesviruses 1, 2, and 6, Epstein-Barr virus, Varicellae-zoster virus (human herpesvirus 3) and cytomegalovirus in blood; determination of anticardiac antibodies; EMB with subsequent PCR-diagnostics including that of parvovirus B19 and pathomorphological study. DNA diagnostics (n = 4), coronary angiography (n = 6), skin biopsy (n = 1) and some other studies were also performed when indicated.</AbstractText><AbstractText Label="RESULTS AND CONCLUSIONS" NlmCategory="CONCLUSIONS">Histological picture was abnormal in all cases. Nosological diagnosis was established in all patients: infectious-immune myocarditis (n = 11), parvovirus positive endomyocarditis (n = 1); systemic vasculitis (n = 2); myocardial vasculitis (n = 1), Fabri disease (n = 1), arrhythmogenic right ventricular dysplasia (ARVD, n = 1), undetermined genetic cardiomyopathy (n = 2). Level of various anticardiac antibodies including antinuclear factor with bovine heart antigen was most valuable for diagnosis of myocarditis (sensitivity 78.6%, prognostic value of positive result 91.7%). The following therapy was used in patients with myocarditis/vasculitis: intravenous or oral acyclovir (n = 10), gabreglobine (n = 2), meloxicam (n = 12), hydroxychloroquine (n = 15 for 15 [7.0; 24.] months), glucocorticosteroids (n = 14 for 18 [4.0; 25.5] months), azathioprine (n = 2). Mean duration of follow up was 4 years (48 [31; 62] months). At baseline 62.5% of patients with AF were resistant to all antiarrhythmic drugs. Treatment of myocarditis resulted in significant reduction of mean frequency of attacks of AF from 8 to 3 points, more than in 40% of patients AF emerged less than once a month and 1 patient had no attacks at all. Disappearance of tachycardia dependent LBBB was also noted. Cardioverter defibrillator and cardiac pacemaker were implanted to patients with ARVD and Fabri disease, respectively. EMB helped to establish immunoinflammatory and genetic diseases as causes of idiopathic arrhythmias (in 78.9 and 21.1% of patients, respectively). Antiviral immunosuppressive therapy of myocarditis allowed to increase efficacy of antiarrhythmic therapy in resistant patients and when necessary to optimize their preparedness to interventional treatment.</AbstractText></Abstract><AuthorList CompleteYN="Y"><Author ValidYN="Y"><LastName>Blagova</LastName><ForeName>O V</ForeName><Initials>OV</Initials></Author><Author ValidYN="Y"><LastName>Nedostup</LastName><ForeName>A V</ForeName><Initials>AV</Initials></Author><Author ValidYN="Y"><LastName>Kogan</LastName><ForeName>E A</ForeName><Initials>EA</Initials></Author><Author ValidYN="Y"><LastName>Sulimov</LastName><ForeName>V A</ForeName><Initials>VA</Initials></Author><Author ValidYN="Y"><LastName>Abugov</LastName><ForeName>S A</ForeName><Initials>SA</Initials></Author><Author ValidYN="Y"><LastName>Kupriianov</LastName><ForeName>A G</ForeName><Initials>AG</Initials></Author><Author ValidYN="Y"><LastName>Zaĭdenov</LastName><ForeName>V A</ForeName><Initials>VA</Initials></Author><Author ValidYN="Y"><LastName>Donnikov</LastName><ForeName>A E</ForeName><Initials>AE</Initials></Author><Author ValidYN="Y"><LastName>Zakliaz'minskaia</LastName><ForeName>E V</ForeName><Initials>EV</Initials></Author></AuthorList><Language>rus</Language><PublicationTypeList><PublicationType UI="D004740">English Abstract</PublicationType><PublicationType UI="D016428">Journal Article</PublicationType></PublicationTypeList></Article><MedlineJournalInfo><Country>Russia (Federation)</Country><MedlineTA>Kardiologiia</MedlineTA><NlmUniqueID>0376351</NlmUniqueID><ISSNLinking>0022-9040</ISSNLinking></MedlineJournalInfo><CitationSubset>IM</CitationSubset><MeshHeadingList><MeshHeading><DescriptorName UI="D000328" MajorTopicYN="N">Adult</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D001145" MajorTopicYN="N">Arrhythmias, Cardiac</DescriptorName><QualifierName UI="Q000209" MajorTopicYN="N">etiology</QualifierName><QualifierName UI="Q000473" MajorTopicYN="Y">pathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D001706" MajorTopicYN="N">Biopsy</DescriptorName><QualifierName UI="Q000379" MajorTopicYN="Y">methods</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D003937" MajorTopicYN="N">Diagnosis, Differential</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D005260" MajorTopicYN="N">Female</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D005500" MajorTopicYN="N">Follow-Up Studies</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D006352" MajorTopicYN="N">Heart Ventricles</DescriptorName><QualifierName UI="Q000473" MajorTopicYN="Y">pathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D006801" MajorTopicYN="N">Humans</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008297" MajorTopicYN="N">Male</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D008875" MajorTopicYN="N">Middle Aged</DescriptorName></MeshHeading><MeshHeading><DescriptorName UI="D009205" MajorTopicYN="N">Myocarditis</DescriptorName><QualifierName UI="Q000150" MajorTopicYN="N">complications</QualifierName><QualifierName UI="Q000473" MajorTopicYN="Y">pathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D009206" MajorTopicYN="N">Myocardium</DescriptorName><QualifierName UI="Q000473" MajorTopicYN="Y">pathology</QualifierName></MeshHeading><MeshHeading><DescriptorName UI="D055815" MajorTopicYN="N">Young Adult</DescriptorName></MeshHeading></MeshHeadingList></MedlineCitation><PubmedData><History><PubMedPubDate PubStatus="entrez"><Year>2014</Year><Month>3</Month><Day>25</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="pubmed"><Year>2013</Year><Month>1</Month><Day>1</Day><Hour>0</Hour><Minute>0</Minute></PubMedPubDate><PubMedPubDate PubStatus="medline"><Year>2014</Year><Month>4</Month><Day>9</Day><Hour>6</Hour><Minute>0</Minute></PubMedPubDate></History><PublicationStatus>ppublish</PublicationStatus><ArticleIdList><ArticleId IdType="pubmed">24654431</ArticleId></ArticleIdList></PubmedData></PubmedArticle><PubmedArticle><MedlineCitation Status="MEDLINE" Owner="NLM"><PMID Version="1">24640727</PMID><DateCompleted><Year>2014</Year><Month>04</Month><Day>08</Day></DateCompleted><DateRevised><Year>2016</Year><Month>11</Month><Day>25</Day></DateRevised><Article PubModel="Print"><Journal><ISSN IssnType="Print">0869-6047</ISSN><JournalIssue CitedMedium="Print"><Issue>11</Issue><PubDate><Year>2013</Year></PubDate></JournalIssue><Title>Vestnik Rossiiskoi akademii meditsinskikh nauk</Title><ISOAbbreviation>Vestn Ross Akad Med Nauk</ISOAbbreviation></Journal>[The prediction of atrial fibrillation in patients with arterial hypertension]. | Aim of the study was to elucidate nosological nature of "idiopathic" arrhythmias by means of right ventricular endomyocardial biopsy (EMB) and to assess effect of etiotropic and pathogenetic treatment.</AbstractText>We included into this study 19 patients (mean age 42.6 +/-11.3 years, 9 women) with atrial fibrillation (AF, n = 16), supraventricular (n = 10) and ventricular (n = 4) extrasystoles (SVE and VE), supraventricular (n = 2) and ventricular (n = 1) tachycardia (SVT and VT), left bundle branch block (LBBB, n = 2), atrioventricular block (n = 2) without structural changes of the heart. In addition to standard examination we performed the following tests: determination of IgG to herpes and Coxsackie B virus, polymerase chain reaction (PCR) for DNA detection of human herpesviruses 1, 2, and 6, Epstein-Barr virus, Varicellae-zoster virus (human herpesvirus 3) and cytomegalovirus in blood; determination of anticardiac antibodies; EMB with subsequent PCR-diagnostics including that of parvovirus B19 and pathomorphological study. DNA diagnostics (n = 4), coronary angiography (n = 6), skin biopsy (n = 1) and some other studies were also performed when indicated.</AbstractText>Histological picture was abnormal in all cases. Nosological diagnosis was established in all patients: infectious-immune myocarditis (n = 11), parvovirus positive endomyocarditis (n = 1); systemic vasculitis (n = 2); myocardial vasculitis (n = 1), Fabri disease (n = 1), arrhythmogenic right ventricular dysplasia (ARVD, n = 1), undetermined genetic cardiomyopathy (n = 2). Level of various anticardiac antibodies including antinuclear factor with bovine heart antigen was most valuable for diagnosis of myocarditis (sensitivity 78.6%, prognostic value of positive result 91.7%). The following therapy was used in patients with myocarditis/vasculitis: intravenous or oral acyclovir (n = 10), gabreglobine (n = 2), meloxicam (n = 12), hydroxychloroquine (n = 15 for 15 [7.0; 24.] months), glucocorticosteroids (n = 14 for 18 [4.0; 25.5] months), azathioprine (n = 2). Mean duration of follow up was 4 years (48 [31; 62] months). At baseline 62.5% of patients with AF were resistant to all antiarrhythmic drugs. Treatment of myocarditis resulted in significant reduction of mean frequency of attacks of AF from 8 to 3 points, more than in 40% of patients AF emerged less than once a month and 1 patient had no attacks at all. Disappearance of tachycardia dependent LBBB was also noted. Cardioverter defibrillator and cardiac pacemaker were implanted to patients with ARVD and Fabri disease, respectively. EMB helped to establish immunoinflammatory and genetic diseases as causes of idiopathic arrhythmias (in 78.9 and 21.1% of patients, respectively). Antiviral immunosuppressive therapy of myocarditis allowed to increase efficacy of antiarrhythmic therapy in resistant patients and when necessary to optimize their preparedness to interventional treatment.</AbstractText> |
13,457 | [Using of a specialized fermented soy milk product on the basis of soybeans in cardiology practice]. | The article is dedicated to the use of a specialized fermented milk product on the basis of soybeans in cardiology practice. 45 patients of both sexes (27 men and 18 women) aged 38 to 69 years (mean age 53.7 +/- 3.1 years) who underwent macrofocal myocardial infarction and abide in the acute period and the period of early rehabilitation have been observed. The data obtained by the comparison of the dynamics of clinical, laboratory and functional parameters in patients, strongly suggests the possibility of increasing the effectiveness of the basic treatment by anti-atherogenic diet with fermented soy drink, enriched with magnesium salts, water-soluble forms of beta-carotene and alpha-tocopherol, ascorbic acid and selenium. 30-35 day inclusion of a fermented soy-based product in comprehensive treatment was accompanied by a marked lipid lowering effect, compared with the standard anti-atherogenic diet. Total cholesterol level in patients from the intervention group (n = 21) decreased by 36.3 per cent, thus reaching the standard level, the corresponding figure in the control group (n = 24) decreased by 24.7 per cent (the difference is statistically significant). Total number of rhythm and conduction disorders in patients receiving product was 1.43 per patient, while it reached 1.83 per patient on the basic therapy and a standard diet. The vast majority were beats, no cases of ventricular fibrillation and one case of atrioventricular block took place in patients from the experimental group. Paroxysmal and atrial fibrillation in the control group of patients were recorded 2 fold more often than in the main group. In addition, three cases of ventricular fibrillation were reported in patients from the control group. Early usage of soy drink 3 fold reduced the incidence of complications in the 10-14 day from the moment of macrofocal myocardial infarction. The frequency of angina attacks per week per patient more significantly reduced under nutritional support, compared with patients receiving standard therapy and diet. The decrease of mean number of nitroglycerin tablets taken per week for one person from the experimental group was equal to 9.0 fold, and in the control group--2.43, this demonstrates a significant strengthening of the effectiveness of basic therapy with early administration of soy product. The recovery of ischemic changes in the electrocardiogram in patients receiving soy product was significantly decreased compared with those receiving standard therapy and anti-atherogenic diet, the degree of reduction in the intervention group was 43.3%, while in the control group--27.5%. These data indicate that the use of soy product in a comprehensive early rehabilitation therapy of patients with macrofocal myocardial infarction significantly reduces the risk of arrhythmias and conduction. |
13,458 | Early repolarization patterns and the role of additional proarrhythmic triggers. | The majority of individuals with early repolarization (ER) patterns have a benign prognosis. However, recent case-control series and population studies have established a significant association between ER and an increased risk of arrhythmic death. There is a common agreement that J-waves, particularly of large amplitude, dynamic, and present in multiple leads, are more prevalent in patients with idiopathic ventricular fibrillation, but the distinction between benign and malignant electrocardiographic variants of ER is still a controversial subject. Some authors have proposed the increased dispersion of repolarization or delayed fragmented depolarization in individuals with J-waves would place them at increased arrhythmic risk, but only in the presence of additional proarrhythmic factors or triggers. The scientific community has therefore embraced research for the identification of those proarrhythmic triggers that could unmask the malignant nature of certain ER variants. This manuscript aims at reviewing very recently published data relating ER patterns and sudden cardiac death in the presence of additional proarrhythmic triggers, in particular acute myocardial ischaemia, focusing on possible pathophysiological and electrogenic mechanisms and therapeutic implications. |
13,459 | Adrenergic receptor polymorphisms and prevention of ventricular arrhythmias with bucindolol in patients with chronic heart failure. | β-blockers prevent cardiac arrhythmias in patients with chronic heart failure and reduced left ventricular ejection fraction, including ventricular tachycardia/ventricular fibrillation (VT/VF). We hypothesized that prevention of ventricular arrhythmias by the β-blocker/sympatholytic agent bucindolol is influenced by genetic variation in adrenergic receptors.</AbstractText>From a substudy of the β-Blocker Evaluation of Survival Trial (n=1040), we identified those with the high functioning 389Arg versus the lower function 389Gly β(1) adrenergic receptor variant, and the loss of function α(2c)322-325 adrenergic receptor deletion versus the 322 to 325 wild-type (Wt)/deletion variant. VT/VF was recorded on case report forms as an adverse event. There were 493 Arg 389 β(1) receptor homozygotes (β(1)389 Arg/Arg) versus 547 Gly389 carriers and 207 α(2c)322-325 deletion carriers versus 833 homozygous Wts (α(2c)322-325 Wt/Wt). In all genotypes bucindolol was associated with a lower incidence of VT/VF (subhazard ratio, 0.42 [0.27-0.64]; P=0.00006). Bucindolol reduced VT/VF in β(1)389 Arg homozygotes (subhazard ratio, 0.26 [0.14-0.50]; P=0.00005) but not in β(1)389 Gly carriers (subhazard ratio, 0.60 [0.34-1.07]; P=0.09). For genotype combinations, the α(2c)322-325 polymorphism altered the VT/VF bucindolol response in β1389 Gly carriers, with α(2c) deletion genotypes associated with complete efficacy loss. A test of interaction was statistically significant (P=0.028) for the treatment group and a β(1)389/α(2c)322-325 three genotype construct, effectively identifying patients who exhibited enhanced response, no substantial response modification and loss of response.</AbstractText>Bucindolol prevents VT/VF in subjects with heart failure and reduced left ventricular ejection fractions, and this effect is modulated by β(1)389 Arg/Gly and α(2c)322-325 Wt/deletion adrenergic receptor polymorphisms.</AbstractText> |
13,460 | The ICD for primary prevention in patients with inherited cardiac diseases: indications, use, and outcome: a comparison with secondary prevention. | Indications for prophylactic implantable cardioverter-defibrillator (ICD) therapy in patients with inherited cardiac diseases stem from observational studies and are uncertain. This study evaluates the efficacy and harm rate of ICD implantations for primary prevention compared with secondary prevention in inherited cardiac diseases.</AbstractText>Between January 1, 1993, and April 1, 2011, 354 patients with inherited cardiac diseases were treated with ICDs. Incidence rates of appropriate shocks in primary prevention patients with arrhythmogenic right ventricular cardiomyopathy and hypertrophic cardiomyopathy were 4.2 to 6.7/100 patient-years, whereas the risk for appropriate shocks in primary prevention patients with Brugada syndrome, long QT syndrome, or carrying the DPP6 haplotype approached zero. Conversely, in secondary prevention patients there was a considerably higher incidence rate of appropriate shocks. None of the indications for primary prevention were associated with appropriate shock therapy. One hundred twenty-three patients (35%) experienced ICD-related adverse events.</AbstractText>For Brugada syndrome, long QT syndrome, and DPP6 the efficacy of an ICD for primary prevention contrasts with the amount of harm, and factors that formed the indication for ICD implantation do not relate to the occurrence of appropriate shocks. The higher appropriate discharge rates in arrhythmogenic right ventricular cardiomyopathy and hypertrophic cardiomyopathy compared with primary electric diseases might result from a more advanced risk stratification scheme in these inherited cardiomyopathies.</AbstractText> |
13,461 | P-wave duration and dispersion in children with uncomplicated familial Mediterranean fever. | This was a prospective controlled study to determine the P-wave duration (Pdu) and P-wave dispersion (Pd) in patients with familial Mediterranean fever (FMF).</AbstractText>The study group consisted of 26 children with uncomplicated FMF and 25 age- and sex-matched healthy controls. We performed electrocardiography (ECG) with Doppler echocardiography on patients and controls. All participants underwent 12-lead electrocardiography under strict standards. Pdu and Pd were computed from a randomly selected beat and from an averaged beat constructed from 12 beats, included in a 10-s ECG.</AbstractText>The left ventricle (LV) dimensions, LV ejection fraction (LVEF), and LV fractional shortening (LVFS) values, left atrium dimension, and aortic dimension were in normal range in both groups. There were significant differences between the groups regarding LV-isovolumic relaxation time (IRT), LV-isovolumic contraction time (ICT), right ventricle (RV)-ICT, RV-IRT, and Pd (all p < 0.0001). However, highly significant positive correlation was detected between LV-ICT, LV-IRT, RV-ICT, RV-IVT, C-reactive protein (CRP), and Pd (r = 0.505, p < 0.0001; r = 0.483, p < 0.0001; r = 0.433, p = 0.001; r = 0.421, p = 0.001; r = 0.452, p = 0.001; r = 0.478, p < 0.0001, respectively).</AbstractText>Uncomplicated FMF children who are continuously treated with colchicine and do not develop amyloidosis have abnormal atrial dispersion and therefore seemingly have an increased electrocardiographic risk of atrial fibrillation.</AbstractText> |
13,462 | Lessons learned from robotic-assisted coronary artery bypass surgery: risk factors for conversion to median sternotomy. | Robotic-assisted coronary artery bypass is a minimally invasive alternative to traditional coronary artery bypass surgery via median sternotomy with an associated learning curve. The purpose of this study was to investigate the reasons for conversion to sternotomy.</AbstractText>From October 2009 to June 2012, two surgeons at one US academic institution performed 271 consecutive robotic-assisted coronary artery bypass procedures. For all cases, isolated, off-pump left internal mammary artery (LIMA) to left anterior descending coronary artery grafting was planned via a 3- to 4-cm sternal-sparing thoracotomy after robotic internal mammary artery harvest and pericardiotomy.</AbstractText>Conversion to sternotomy occurred in 15 of 271 (5.5%) patients. The most common reason was technical difficulty with the anastomosis, which occurred in 6 (40.0%) patients. Others included LIMA dissection, 2 (13.3%); wrong vessel grafted, 2 (13.3%); ventricular fibrillation and cardiac arrest, 1 (6.7%); equipment malfunction, 1 (6.7%); adhesions, 1 (6.7%); and other. Two underwent emergent conversion. Six underwent multivessel bypass after conversion instead of hybrid coronary revascularization. No mortality occurred among converted patients. Two patients had postoperative myocardial infarction and one had a superficial sternal wound infection. Conversion rate was relatively stable among the four different time quartiles (range, 3.0%-7.4%), although the reasons for conversion were different.</AbstractText>Conversion to sternotomy is an infrequent complication of robotic-assisted coronary artery bypass, most commonly because of technical difficulties during the LIMA harvest and the LIMA to left anterior descending anastomosis. Anatomic and patient variables as well as inherent technical problems with minimally invasive procedures make conversion unavoidable in some patients.</AbstractText> |
13,463 | A novel pacing method to suppress repolarization alternans in vivo: implications for arrhythmia prevention. | Repolarization alternans (RA), a pattern of ventricular repolarization that repeats on an every other beat basis, has been closely linked with the substrate associated with ventricular tachycardia/ventricular fibrillation.</AbstractText>To evaluate a novel method to suppress RA.</AbstractText>We have developed a novel method to dynamically (on R-wave detection) trigger pacing pulses during the absolute refractory period. We have tested the ability of this method to control RA in a structurally normal swine heart in vivo.</AbstractText>RA induced by triggered pacing can be measured from both intracardiac and body surface leads and the amplitude of R-wave triggered pacing-induced alternans can be locally modulated by varying the amplitude and width of the pacing pulse. We have estimated that to induce a 1 μV change in alternans voltage on the body surface, coronary sinus, and left ventricle leads, a triggered pacing pulse delivered in the right ventricle of 0.04±0.02, 0.05±0.025, and 0.06±0.033 μC, respectively, is required. Similarly, to induce a 1 unit change in Kscore (ratio of alternans peak to noise), a pacing stimulus of 0.93±0.73, 0.32±0.29, and 0.33±0.37 μC, respectively, is required. We have been able to demonstrate that RA can be suppressed by R-wave triggered pacing from a site that is within or across ventricles. Lastly, we have demonstrated that the proposed method can be used to suppress spontaneously occurring alternans in the diseased heart.</AbstractText>We have developed a novel method to suppress RA in vivo.</AbstractText>Copyright © 2013. Published by Elsevier Inc.</CopyrightInformation> |
13,464 | The prognostic value of early repolarization (J wave) and ST-segment morphology after J wave in Brugada syndrome: multicenter study in Japan. | The prognostic value of a J wave and ST-segment morphology after J wave in inferolateral leads in Brugada syndrome (BS) is still unknown.</AbstractText>To evaluate the prognostic value of a J wave and ST-segment morphology after J wave in a large Japanese cohort of BS.</AbstractText>A total of 460 consecutive patients with BS (mean age 52±14 years, 432 men) were enrolled. The presence and location of leads showing a J wave, ST-segment morphology after J wave, and clinical outcomes were evaluated in patients with documented ventricular fibrillation (VF) (N = 84), those with syncope without documented VF (N = 109), and subjects without symptoms (N = 267).</AbstractText>The prevalence of a J wave in the inferior and/or lateral leads was 12% (53 cases). The prevalence of a J wave among the 3 groups was not different. The incidence of cardiac events (sudden cardiac death or VF) during a mean follow-up period of 50±32 months was not different in patients with (11%) or without (8%) a J wave. Patients with a J wave in both inferior and lateral leads or with horizontal ST-segment morphology after J wave showed a higher incidence of cardiac events than those without (P = .04 and .02, respectively). Multivariate analysis revealed symptoms, QRS duration in lead V2>90 ms, and inferolateral J wave and/or horizontal ST-segment morphology after J wave were important for predicting cardiac events.</AbstractText>The presence of a J wave in multiple leads and horizontal ST-segment morphology after J wave may indicate a highly arrhythmogenic substrate in patients with BS.</AbstractText>Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,465 | MicroRNA regulation of cardiac conduction and arrhythmias. | MicroRNAs are now recognized as important regulators of cardiovascular genes with critical roles in normal development and physiology, as well as disease development. MicroRNAs (miRNAs) are small noncoding RNAs approximately 22 nucleotides in length that regulate expression of target genes through sequence-specific hybridization to the 3' untranslated region of messenger RNAs and either block translation or direct degradation of their target messenger RNA. They have been shown to participate in cardiovascular disease pathogenesis including atherosclerosis, coronary artery disease, myocardial infarction, heart failure, and cardiac arrhythmias. Broadly defined, cardiac arrhythmias are a variation from the normal heart rate or rhythm. Arrhythmias are common and result in significant morbidity and mortality. Ventricular arrhythmias constitute a major cause for cardiac death, particularly sudden cardiac death in the setting of myocardial infarction and heart failure. As advances in pharmacologic, device, and ablative therapy continue to evolve, the molecular insights into the basis of arrhythmia is growing with the ambition of providing additional therapeutic options. Electrical remodeling and structural remodeling are identified mechanisms underlying arrhythmia generation; however, published studies focusing on miRNAs and cardiac conduction are sparse. Recent studies have highlighted the role of miRNAs in cardiac rhythm through regulation of key ion channels, transporters, and cellular proteins in arrhythmogenic conditions. This article aims to review the studies linking miRNAs to cardiac excitability and other processes pertinent to arrhythmia. |
13,466 | Relation of heart-rate recovery to new onset heart failure and atrial fibrillation in patients with diabetes mellitus and preserved ejection fraction. | Diabetic autonomic neuropathy is a possible link between abnormal metabolism in type 2 diabetes mellitus (T2DM) and risk for atrial fibrillation (AF) and heart failure (HF). The aim of this study was to elucidate the association between attenuated heart rate recovery (HRR) and these manifestations of myocardial dysfunction in T2DM. Nine hundred fourteen consecutive patients with T2DM (mean age 56 ± 11 years, 508 men) without diabetes mellitus complications, with negative results on stress echocardiography, were enrolled. Patients with known cardiac disease were excluded. Demographics, clinical assessment, co-morbidities, and insulin use were collected prospectively. The association of HRR with new-onset HF and AF was sought using a Cox proportional-hazards model. There were 47 events (22 HF and 25 AF) during a median follow-up period of 7.8 years. Events were associated with age, exercise capacity, HRR, and left atrial volume index but not with baseline glycosylated hemoglobin, left ventricular mass index, or standard markers of diastolic function. In sequential Cox models for the combined outcomes, the model based on clinical data (age and gender; overall chi-square = 5.5) was not significantly improved by left atrial volume index (chi-square = 8.6, p = 0.10) or maximum METs (chi-square = 8.7, p = 0.07) but was significantly improved by adding HRR (chi-square = 19.7, p = 0.004). In addition, HRR provided significant incremental prognostic value regarding the composite end point (net reclassification improvement 19.2%, p = 0.04; integrated discrimination improvement 1.58%, p = 0.004). In conclusion, the association of HRR with subsequent HF and AF, independent of and incremental to left atrial volume index and other markers of abnormal cardiac structure and function, indicates a role for autonomic neuropathy as the link between metabolic and cardiac risk in patients with T2DM. |
13,467 | Tranilast prevents atrial remodeling and development of atrial fibrillation in a canine model of atrial tachycardia and left ventricular dysfunction. | This study sought to assess the effects of tranilast on atrial remodeling in a canine atrial fibrillation (AF) model.</AbstractText>Tranilast inhibits transforming growth factor (TGF)-β1 and prevents fibrosis in many pathophysiological settings. However, the effects of tranilast on atrial remodeling remain unclear.</AbstractText>Beagles were subjected to atrial tachypacing (400 beats/min) for 4 weeks while treated with placebo (control dogs, n = 8) or tranilast (tranilast dogs, n = 10). Sham dogs (n = 6) did not receive atrial tachypacing. Atrioventricular conduction was preserved. Ventricular dysfunction developed in the control and tranilast dogs due to rapid ventricular responses.</AbstractText>Atrial fibrillation duration (211 ± 57 s) increased, and AF cycle length and atrial effective refractory period shortened in controls, but these changes were suppressed in tranilast dogs (AF duration, 18 ± 10 s, p < 0.01 vs. control). The L-type calcium channel α1c (Cav1.2) micro ribonucleic acid expression decreased in control dogs (sham 1.38 ± 0.24 vs. control 0.65 ± 0.12, p < 0.01), but not in tranilast dogs (0.97 ± 0.14, p = not significant vs. sham). Prominent atrial fibrosis (fibrous tissue area, sham 0.8 ± 0.1 vs. control 9.3 ± 1.3%, p < 0.01) and increased expression of tissue inhibitor of metalloproteinase protein 1 were observed in control dogs but not in tranilast dogs (fibrous tissue area, 1.4 ± 0.2%, p < 0.01 vs. control). The TGF-β1 (sham 1.00 ± 0.07 vs. control 3.06 ± 0.87, p < 0.05) and Rac1 proteins were overexpressed in control dogs, but their overexpression was inhibited in tranilast dogs (TGF-β1, 1.28 ± 0.20, p < 0.05 vs. control).</AbstractText>Tranilast prevented atrial remodeling and suppressed AF development in a canine model. Its inhibition of TGF-β1 and Rac1 overexpression may contribute to its antiremodeling effects.</AbstractText>Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,468 | [Negative result of microvolt T-wave alternans test is helpful in scheduling the order of cardioverter-defibrillator implantation in primary prevention of sudden cardiac death in individuals with the left ventricular systolic dysfunction]. | Implantation of cardiac cardioverter-defibrillator (ICD) is an established modality in the primary prevention of sudden cardiac death (SCD) in patients (pts) with left ventricular systolic dysfunction. However, fulfillment of this recommendation in our country is associated with a substantial increase in healthcare costs and results in a progressive elongation of waiting lines comprised of individuals qualified to ICD implantation. Consequently, this situation substantiates the search for additional noninvasive markers enabling the stratification of patients into high- and low risk groups so that the order of ICD implantation procedures favors those at higher risk. Analysis of microvolt T-wave alternans (MTWA) can be a helpful test in this matter. The aim of this study was to analyze the incidence of SCD episodes and malignant ventricular arrhythmias (ventricular tachycardia - VT, and ventricular fibrillation - VF) in a group of pts with left ventricular systolic dysfunction who were qualified to ICD implantation in primary prevention of SCD and had negative result of MTWA test.</AbstractText>The study included pts with left ventricular ejection fraction (LVEF) < or =35%, who were qualified to ICD implantation in primary prevention of SCD and had negative result of MTWA (spectral method, CH2000 system, Cambridge Heart). Pts were followed up (scheduled visits every 3 months) and, among others, screened for adverse events (SCD/VT/VF).</AbstractText>Of 115 pts analyzed for MTWA in the course of qualification to ICD implantation, 49 individuals (mean age 58 +/- 13 years, LVEF 30 +/- 6%) were enrolled to further analysis due to negative result of this test. The duration of follow up was 9 +/- 7 months. None of analyzed pts had episodes of SCD/ VF/VT.</AbstractText>On follow up, SCD/VT/VF episodes were not recorded amongst patients with left ventricular systolic dysfunction who were qualified to ICD implantation in primary prevention of SCD and had negative results of MTWA test. After taking other potential risk factors into account, the negative MTWA result will probably enable identification of patients in whom the implantation can be postponed in favor of individuals who urgently require this procedure. However, further studies are needed to confirm these preliminary findings.</AbstractText> |
13,469 | Various morphologies of bidirectional ventricular tachycardia caused by aconite "Torikabuto" poisoning. | A 43-year-old man presented with nausea. The patient developed ventricular fibrillation (VF), which was refractory to antiarrhythmic drugs and defibrillation. A coronary angiogram showed no coronary artery stenosis. We recorded various fatal arrhythmias, including bidirectional ventricular tachycardia (BVT). The presence of multiple types of BVTs that were refractory to drugs such as adenosine triphosphate, isoproterenol, verapamil, propranolol, and pilsicainide, and easily recurred after defibrillation indicated aconite poisoning. After persisting for 24 h, VF spontaneously resolved and sinus rhythm was restored. Laboratory data revealed lethal concentrations of aconitine. To the best of our knowledge, this is the first report of aconite poisoning-induced BVTs manifesting with multiple morphologies on 12-lead electrocardiogram. The arrhythmogenic effects of aconitine are well recognized. In addition to causing VT and VF, aconitine also can cause BVT. Aconitine can lead to delayed afterdepolarization which has an important role in triggering and maintaining BVT. However, in this case, the concentration of aconitine was high enough to render these drugs ineffective. Prompt application of percutaneous cardio-pulmonary support, which was continued until the aconitine was metabolized, proved successful in this case and should be considered as a management approach in cases of severe aconite poisoning. |
13,470 | Predictors of new-onset heart failure: differences in preserved versus reduced ejection fraction. | About one half of patients with heart failure (HF) have preserved ejection fraction (HFPEF) rather than reduced ejection fraction (HFREF). The differences in risk factors predisposing to the 2 subtypes of HF are poorly understood. We sought to identify clinical predictors of new-onset HF and to explore differences in HFPEF versus HFREF.</AbstractText>We studied new-onset HF cases between 1981 and 2008 in Framingham Heart Study participants, classified into HFPEF and HFREF (ejection fraction >45% versus ≤45%). We used Cox multivariable regression to examine predictors of 8-year risk of incident HF and competing-risks analysis to identify predictors that differed between HFPEF and HFREF. Among 6340 participants (60±12 years) with 97 808 person-years of follow-up, 512 developed incident HF. Of 457 participants with left ventricular ejection fraction evaluation at the time of HF diagnosis, 196 (43%) were classified as HFPEF and 261 (56%) as HFREF. Fourteen predictors of overall HF were identified. Older age, diabetes mellitus, and a history of valvular disease predicted both types of HF (P≤0.0025 for all). Higher body mass index, smoking, and atrial fibrillation predicted HFPEF only, whereas male sex, higher total cholesterol, higher heart rate, hypertension, cardiovascular disease, left ventricular hypertrophy, and left bundle-branch block predicted risk of HFREF.</AbstractText>Although multiple risk factors preceded overall HF, distinct clusters of risk factors determine risk for new-onset HFPEF versus HFREF. This knowledge may enable the design of clinical trials of targeted prevention and the introduction of therapeutic strategies for prevention of HF and its 2 major subtypes.</AbstractText> |
13,471 | Motion of left atrial appendage as a determinant of thrombus formation in patients with a low CHADS2 score receiving warfarin for persistent nonvalvular atrial fibrillation. | The aim of this study was to define the independent determinants of left atrial appendage (LAA) thrombus among various echocardiographic parameters measured by Velocity Vector Imaging (VVI) in patients with nonvalvular atrial fibrillation (AF) receiving warfarin, particularly in patients with a low CHADS2 score.</AbstractText>LAA emptying fraction (EF) and LAA peak longitudinal strain were measured by VVI using transesophageal echocardiography in 260 consecutive patients with nonvalvular persistent AF receiving warfarin. The patients were divided into two groups according to the presence (n=43) or absence (n=217) of LAA thrombus. Moreover, the patients within each group were further divided into subgroups according to a CHADS2 score ≤1.</AbstractText>Multivariate logistic regression analysis showed that LAAEF was an independent determinant of LAA thrombus in the subgroup of 140 with a low CHADS2 score. Receiver operating characteristics curve analysis showed that an LAAEF of 21% was the optimal cutoff value for predicting LAA thrombus.</AbstractText>LAA thrombus formation depended on LAA contractility. AF patients with reduced LAA contractile fraction (LAAEF ≤21%) require strong anticoagulant therapy to avoid thromboembolic events regardless of a low CHADS2 score (≤1).</AbstractText> |
13,472 | Effect of rescue breathing during cardiopulmonary resuscitation on lung function after restoration of spontaneous circulation in a porcine model of prolonged cardiac arrest. | The destruction of the pulmonary structure after cardiopulmonary resuscitation may lead to lung function breakdown. The aim of this study was to investigate lung function after cardiopulmonary resuscitation and the influence of rescue breathing on lung function.</AbstractText>Prospective, randomized animal study.</AbstractText>A university animal research laboratory.</AbstractText>Twenty-eight male domestic pigs weighing 30 ± 2 kg.</AbstractText>The animals were randomized into three groups: continuous compressions (n = 12), 30:2 compression/rescue ventilation cardiopulmonary resuscitation (n = 12), and sham cardiopulmonary resuscitation (n = 4). Ventricular fibrillation was induced in the continuous compressions and compression/rescue ventilation groups.</AbstractText>Cardiac output, extravascular lung water, and airway resistance were measured at baseline and 1, 2, and 4 hrs after restoration of spontaneous circulation. Thoracopulmonary compliance, lower inflection point, and dead space were calculated. Lung ventilation/perfusion scans with Tc were performed 48 hrs before the experiment and 24 hrs after restoration of spontaneous circulation. Conventional histopathology evaluation was performed. Dead space, airway resistance, lower inflection point, and extravascular lung water significantly increased and compliance decreased after restoration of spontaneous circulation in the continuous compressions and compression/rescue ventilation groups. Lung injury was more severe in the continuous compressions group. Significant differences were found between the two groups in the three time points after restoration of spontaneous circulation (p < 0.05). Variables of the sham cardiopulmonary resuscitation group remained stable during the whole protocol. Poor ventilation/perfusion and mismatch were found after restoration of spontaneous circulation, but the injury was mitigated in the compression/rescue ventilation group. Histopathology injury in the compression/rescue ventilation group was also improved.</AbstractText>Appropriate rescue breathing during cardiopulmonary resuscitation does not influence the prognosis of cardiac arrest or the hemodynamics after restoration of spontaneous circulation but can improve lung function and alleviate lung injury.</AbstractText> |
13,473 | [Surgical correction of tetralogy of Fallot in adults over 40 years of age]. | To summarize the experience with surgical correction of tetralogy of Fallot in adults over 40 years of age.</AbstractText>From November 1985 to July 2008, 9 male and 11 female patients aged 41-53 years (mean 46.3±3.5 years) underwent total surgical correction for tetralogy of Fallot. Twelve patients had preoperative NYHA class III cardiac function. The common comorbidities included infective endocarditis, cerebral abscess, cerebral infarction, renal dysfunction, and tricuspid insufficiency. Surgical corrections were carried out at the anatomical or physiological level.</AbstractText>Nineteen patients received right ventriculotomy to relieve right ventricular outflow obstruction and for ventricular septal defect closure, and 1 patient had Fontan operation. Two patients died after the surgery for heart failure and ventricular fibrillation. The average cardiopulmonary bypass time, aortic clamp time, and postoperative ventilation time was 142.9±36.3 min, 89.9±25.1 min, and 72.0±17.5 h, respectively. Postoperative low cardiac output syndrome occurred in 5 cases, septic shock in 1 case, secondary renal failure in 1 case, and bleeding in 2 cases. Echocardiography showed a significant postoperative reduction of the mean right ventricular outflow tract velocity from 4.29±1.36 m/s to 2.13±0.83 m/s (P<0.01); the right ventricular longitudinal dimension exhibited no significant changes postoperatively (57.1±6.7 mm vs 55.1±7.0 mm, P=0.65).</AbstractText>Surgical correction of the tetralogy of Fallot in patients over 40 years is highly risky and requires appropriate management of cardiac failure, careful myocardial protection, and thorough intracardiac lesion correction to decrease surgical complications.</AbstractText> |
13,474 | Does management of cardiac arrest scenarios differ between residents of different disciplines? A comparison with simulation. | Training multidisciplinary teams using simulation allows for communication, development and maintenance of teamwork. In this study we compared the behavior of residents from emergency and anesthesiology departments on treatment of cardiac arrest.</AbstractText>42 anesthesiology and 29 emergency residents are included in the study. Two scenarios were designed for diagnosis and treatment of asystole and ventricular fibrillation. First scenario was a case with ventricular fibrillation (VF) and the second was an asystole case. ACLS protocols were used for assessment. Age, years of training, and years in practice were compared for each group.</AbstractText>Anesthesiology residents attempted to secure the airway immediately after checking the carotid pulse and began the cardiac compressions. After intubation, the vast majority (88%) of participants monitorized the patient. Only 11.9% of the residents started compressions and were reminded to monitorize the patient. Emergency residents immediately started CPR with compressions and ventilation by mask. 79.3% of them decided to intubate after a few compressions but 20.7% of them didn't attempt it. 50% of the residents monitorized the simulator whereas the other half was reminded to. There was no significant difference between the groups in terms of ventricular fibrillation and asystole management, but the age of the doctors was a decisive factor affecting the success in the VF simulation.</AbstractText>This study demonstrates the use of simulation to identify the deficiencies in basic knowledge and the skills of emergency and anesthesiology residents. It highlights the need to emphasize criteria that should be used in resuscitation.</AbstractText> |
13,475 | Venturing into ventricular arrhythmia storm: a systematic review and meta-analysis. | Ablation has substantial evidence base in the management of ventricular arrhythmia (VA). It can be a 'lifesaving' procedure in the acute setting of VA storm. Current reports on ablation in VA storm are in the form of small series and have relative small representation in a large observational series. The purpose of this study was to systematically synthesize the available literature to appreciate the efficacy and safety of ablation in the setting of VA storm. The medical electronic databases through 31 January 2012 were searched. Ventricular arrhythmia storm was defined as recurrent (≥ 3 episodes or defibrillator therapies in 24 h) or incessant (continuous >12 h) VA. Studies reporting data on VA storm patients at the individual or study level were included. A total of 471 VA storm patients from 39 publications were collated for the analysis. All VAs were successfully ablated in 72% [95% confidence interval (CI) 71-89%] and 9% (95% CI: 3-10%) had a failed procedure. Procedure-related mortality occurred in three patients (0.6%). Only 6% patients had a recurrence of VA storm. The recurrence of VA was significantly higher after ablation for arrhythmic storm of monomorphic ventricular tachycardia (VT) relative to ventricular fibrillation or polymorphic VT with underlying cardiomyopathy (odds ratio 3.76; 95% CI: 1.65-8.57; P = 0.002). During the follow-up (61 ± 37 weeks), 17% of patients died (heart failure 62%, arrhythmias 23%, and non-cardiac 15%) with 55% deaths occurring within 12 weeks of intervention. The odds of death were four times higher after a failed procedure compared with those with a successful procedure (95% CI: 2.04-8.01, P < 0.001). Ventricular arrhythmia storm ablation has high-acute success rates, with a low rate of recurrent storms. Heart failure is the dominant cause of death in the long term. Failure of the acute procedure carries a high mortality. |
13,476 | Factors predisposing to ventricular tachyarrhythmia leading to appropriate ICD intervention in patients with coronary artery disease or non-ischaemic dilated cardiomyopathy. | In order to achieve optimal outcomes when treating ventricular tachyarrhythmias with implantable devices, it is extremely important to identify parameters predisposing to arrhythmia. In view of current restrictions in healthcare funding, there is a growing demand for additional predictors of arrhythmia that would allow better patient selection for implantable cardioverter-defibrillator (ICD) use for primary prevention of sudden cardiac death (SCD).</AbstractText>To identify parameters predisposing to ventricular tachyarrhythmia/appropriate ICD intervention in ICD recipients.</AbstractText>We analysed 376 patients (56 women, 320 men, mean age 66.1 ± 11.2 [range 22-89] years) who underwent ICD implantation between January 2008 and December 2010. Of these, 275 patients underwent ICD implantation for primary prevention of SCD and 101 for secondary prevention. Operative protocols and in-hospital and outpatient records were analysed retrospectively. Mean QRS width and heart rate (HR) were calculated in resting surface electrocardiograms (25 mm/s, 10 mm/1 mV). Intracardiac electrograms stored in ICD memory were used to evaluate appropriateness of anti-arrhythmic interventions and analyse the number of ventricular tachyarrhythmia events, ICD interventions and their type. We analysed the following clinical and procedural variables: age, gender, left ventricular ejection fraction (LVEF), type of SCD prevention (primary or secondary), ICD type (single chamber--VR, dual chamber--DR), performing defibrillation threshold testing to establish defibrillation safety margin at ICD implantation, ventricular lead location (right ventricular outflow tract region, right ventricular apex), mean HR, QRS width, New York Heart Association (NYHA) functional class, occurrence of ventricular tachyarrhythmia/appropriate ICD intervention after implantation, ICD interventions, history of cardiovascular disease and arrhythmia (myocardial infarction, ischaemic and non-ischaemic dilated cardiomyopathy, arterial hypertension, ventricular fibrillation, ventricular tachycardia, permanent atrial fibrillation, percutaneous coronary intervention, and/or coronary artery bypass grafting), and medications (amiodarone, sotalol, beta-blockers, angiotensin-converting enzyme inhibitors [ACEI]/angiotensin receptor blockers [ARB], statins, loop diuretics, aldosterone antagonists).</AbstractText>During the mean follow-up period of 387 ± 300 (range 5-1400) days, appropriate ICD intervention due to ventricular tachyarrhythmia occurred in 68 of 376 ICD patients (61 men, 7 women, mean age 64.7 ± 12.3 [range 22-89] years). Mean time interval from ICD implantation to the occurrence of arrhythmia was 281 ± 229 (range 5-972) days (p 〈 0.001). To optimize sensitivity and specificity when analysing ventricular tachyarrhythmia/appropriate ICD intervention vs. no ventricular tachyarrhythmia/appropriate ICD intervention, cutoff values were established using ROC curves (cutoff for LVEF = 31%, HR = 79 bpm). Using these cutoff values, patients with ventricular tachyarrhythmia/appropriate ICD intervention were compared to those without ventricular tachyarrhythmia/appropriate ICD intervention. Significant differences were observed in LVEF (p< 0.001), HR (p< 0.022), ACEI/ARB use (p< 0.034), and NYHA class (p< 0.001). By Kaplan-Meier univariate analysis, patients with LVEF> 31% (log-rank test p< 0.001), HR ≤ 79 bpm (log-rank test p< 0.022), QRS width ≤ 114 ms (log-rank test p < 0.045), and NYHA class II (log-rank test p< 0.001) were more likely to be free from ventricular tachyarrhythmia/appropriate ICD intervention. Cox multivariate analysis showed that reduced LVEF (≤ 31%) was the only independent predictor of arrhythmia/intervention. LVEF values below 31% are associated with a significant 20-fold increase (p< 0.02) in the risk of arrhythmia during the first 3 years after ICD implantation. Among 68 patients with ventricular tachyarrhythmia/appropriate ICD intervention, mean 4.1 interventions per person occurred during the follow-up period. In the overall study population, the number of interventions was 0.28 per person per year. Overall, 92 inappropriate ICD interventions were observed, all resulting from atrial fibrillation with rapid ventricular rate. Interventions had no effect on total mortality. Higher numbers of appropriate interventions were observed in patients who died due to heart failure.</AbstractText>Factors associated with a significantly increased risk of ventricular tachyarrhythmia/appropriate ICD intervention included reduced LVEF, increased resting HR, NYHA class II or higher heart failure, and wide QRS. Patients with low LVEF (< 31%) are at particular risk of SCD due to ventricular arrhythmia and this parameter alone can influence the decision regarding ICD implantation. No effect of ICD interventions on total mortality was observed, although more ICD interventions were observed in patients who died due to heart failure.</AbstractText> |
13,477 | Trimetazidine demonstrated cardioprotective effects through mitochondrial pathway in a model of acute coronary ischemia. | Myocardial ischemia affects mitochondrial function leading to ionic imbalance and susceptibility to ventricular fibrillation. Trimetazidine (TMZ), a metabolic agent, is clinically used as an anti-anginal therapy. This study was conducted to compare the effect of TMZ 20 mg immediate release (IR) and TMZ 35 mg modified release (MR), two bioequivalent marketed formulations of TMZ, on cardioprotection during acute ischemia in pigs. A 4-day oral treatment with TMZ 20 mg IR (800 mg, tid) or TMZ 35 mg MR (1,400 mg, bid) had no effect on ventricular fibrillation threshold (VFT) prior to ischemia but significantly prevented the decrease in VFT observed in placebo-treated groups after a 1-min left anterior descending coronary artery occlusion. This effect occurred without modifying cardiac hemodynamic and conduction parameters. In both TMZ-treated groups, a significant reduction of the ischemic area as well as a protection of cardiomyocytes were observed. Cardiac enzymatic activity (phosphorylase, succinate dehydrogenase, ATPase) was increased in TMZ-treated groups. Both formulations preserved mitochondrial structure and improved mitochondrial function as demonstrated by a twofold increase of oxidative phosphorylation, by a reduction of reactive oxygen species (ROS) production (>30 %) and by a trend to increase the mitochondrial calcium retention capacity. In this model of ischemia, both TMZ formulations, leading to equivalent TMZ plasma exposures, demonstrated similar cardioprotective effects. This protection could be attributed to a preservation of mitochondrial structure and function, which plays a central role in ATP and ROS production and consequently could be considered as a target of cardioprotection. |
13,478 | Does post-cardiac surgery magnesium supplementation improve outcome? | Hypomagnesemia has been linked with increased morbidity and mortality in critically ill patients. Since the condition is common after cardiopulmonary bypass surgery, the objective of this study was to determine whether magnesium supplementation in the immediate postoperative period may improve outcomes of patients undergoing cardiac surgery with cardiopulmonary bypass. This prospective, randomized, double-blind, placebo-controlled study was conducted in a third-level, cardiac surgery intensive care unit (ICU) at a university hospital. Two hundred and sixteen patients undergoing elective cardiac surgery with cardiopulmonary bypass were randomized to receive either an intravenous bolus of 1.5 g of magnesium sulphate followed by an infusion of 12 g of the same salt in 24 h (105 patients), or placebo (111 patients) administered according to the same schedule as the treatment group. No significant differences were found either in the primary end point (hours of intubation) or in the secondary end points (length of inotropic support, new atrial fibrillation, ventricular tachycardia or ventricular fibrillation, length of intensive care unit stay, or ICU or hospital mortality). Hypomagnesemia was present in 12% of patients on admission to the intensive care unit. The magnesium group had a greater need for pacemaker stimulation. In conclusion, under the conditions of the present study, magnesium supplementation after cardiac surgery with cardiopulmonary bypass does not favourably affect clinical outcomes. |
13,479 | Early to midterm results of total cavopulmonary connection in adult patients. | Total cavopulmonary connection (TCPC) has not been studied in adults. We investigated early and midterm morbidity and mortality in adults undergoing TCPC and assessed risk factors for mortality.</AbstractText>Between June 1994 and October 2010, 30 adults (21.3 ± 5.5 years) underwent TCPC (extracardiac conduit). Twenty-two patients who had palliated single ventricles underwent TCPC completions and 8 patients underwent TCPC conversions. Preoperative and perioperative data were reviewed retrospectively.</AbstractText>Six of 9 patients with preoperative atrial flutter or fibrillation or intraatrial reentry tachycardia were treated in the catheterization room. An aortic cross-clamp was necessary in 12 patients, and 16 TCPCs were fenestrated. Mean follow-up was 51 months (range, 4-198 months). Early mortality was 10%: 2 of 8 conversions and 1 of 22 completions. There was 1 late conversion death (at 56 months postoperatively). Postoperatively, 4 patients required pacemakers and 1 patient required long-term antiarrhythmic medication, but no heart transplantations were necessary. Risk factors for early mortality were arrhythmia (p = 0.02), aortic cross-clamp (p = 0.054), and extracorporeal circulation in hypothermia (p = 0.03). Risk factors for overall mortality were conversion (p = 0.047), absence of fenestration (p = 0.036), surgery before January 2006 (p = 0.036), aortic cross-clamp (p = 0.018), extracorporeal circulation in hypothermia (p = 0.008), and arrhythmia (p = 0.005). New York Heart Association functional class had improved at the last follow-up: preoperatively, 17 patients were in class II and 12 patients were in class III versus 18 patients in class I and 9 patients in class II postoperatively (p < 0.001). At the last clinical visit, systemic ventricular function was maintained, and no late supraventricular arrhythmia was found.</AbstractText>Early and midterm TCPC results for adults are encouraging for completion but are disappointing for conversion. Identified risk factors for mortality should improve patient selection for TCPC.</AbstractText>Copyright © 2013 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.</CopyrightInformation> |
13,480 | Synthesis and evaluation of diphenylphosphinic amides and diphenylphosphine oxides as inhibitors of Kv1.5. | Diphenylphosphinic amides and diphenylphosphine oxides have been synthesized and tested as inhibitors of the Kv1.5 potassium ion channel as a possible treatment for atrial fibrillation. In vitro structure-activity relationships are discussed and several compounds with Kv1.5 IC(50) values of <0.5 μM were discovered. Selectivity over the ventricular IKs current was monitored and selective compounds were found. Results from a rabbit PD-model are included. |
13,481 | Neutrophil to lymphocyte ratio and cardiovascular diseases: a review. | The role of inflammatory markers in cardiovascular diseases has been studied extensively and a consistent relationship between various inflammatory markers and cardiovascular diseases has been established in the past. Neutrophil to lymphocyte ratio (NLR) is a new addition to the long list of these inflammatory markers. NLR, which is calculated from complete blood count with differential, is an inexpensive, easy to obtain, widely available marker of inflammation, which can aid in the risk stratification of patients with various cardiovascular diseases in addition to the traditionally used markers. It has been associated with arterial stiffness and high coronary calcium score, which are themselves significant markers of cardiovascular disease. NLR is reported as an independent predictor of outcome in stable coronary artery disease, as well as a predictor of short- and long-term mortality in patients with acute coronary syndromes. It is linked with increased risk of ventricular arrhythmias during percutaneous coronary intervention (PCI) and higher long-term mortality in patients undergoing PCI irrespective of indications of PCI. In patients admitted with advanced heart failure, high NLR was reported with higher inpatient mortality. Recently, NLR has been reported as a prognostic marker for outcome from coronary artery bypass grafting and postcoronary artery bypass grafting atrial fibrillation. |
13,482 | Linear catheter ablation of the right atrium for rapid atrial pacing-induced sustained atrial fibrillation in dogs. | Catheter ablation of persistent/long-persistent atrial fibrillation (AF) has been shown to be less effective by pulmonary vein isolation (PVI) and additional left atrial (LA) complex fractionated atrial electrograms and long linear lesions are often required. Recent reports have demonstrated right atrial (RA) ablation increases the success rate of maintaining sinus rhythm in persistent/long-persistent AF. The aim of this study was to investigate whether effective RA linear lesions can terminate AF and render it noninducible in a canine model of rapid atrial pacing-induced sustained AF. Sustained AF was induced by rapid atrial pacing in 20 dogs. AF duration was 21-126 days (median, 50 days). Four RA linear lesions (superior vena cava-inferior vena cava, septal line, transverse line, and cavo-tricuspid line) were created with the use of 1 of 3 different ablation catheters (large-tip [8-mm tip], coil-tip, and cooled-tip catheters). AF was terminated with the large-tip catheter in 4/7 dogs (1 dog died of ventricular fibrillation [VF]), with the coil-tip catheter in 3/7 dogs (1 dog died of VF), and with the cooled-tip catheter in 1/6 dogs. In 6 dogs in which AF could not be terminated acutely by RA ablation, AF terminated spontaneously at 7-78 days (median, 14 days) after ablation. RA linear ablation terminated AF with limited success in our dog model of rapid atrial pacing-induced AF, but late AF termination was noted in the surviving dogs. Therefore, RA linear lesions in addition to the PVI and LA lesions may have additional effects on the catheter ablation for the persistent AF. |
13,483 | Does reducing unnecessary right ventricular pacing improve sympathetic activity and innervation of heart in sinus node disease patients? MVP and SafeR study. | Ventricular desynchronization imposed by ventricular pacing causes regional disturbances of adrenergic innervation in the left ventricular myocardium and increases the risk of heart failure and atrial fibrillation (AF) in patients with sinus node disease (SND). As a result, decreased iodine-123 metaiodobenzylguanidine (I-(123 )MIBG) uptake occurs in patients with an implanted permanent pacemaker. Fourteen SND patients with an implanted pacemaker equipped with an algorithm for reducing unnecessary right ventricular pacing (RURVP) were enrolled. Pacemakers were programmed to RURVP mode for the first 12 weeks, and then reprogrammed to DDD for the last 12 weeks. At the end of each mode, data on cumulative percent ventricular pacing (%Vp), atrial high rate episodes (%AHR), I-(123 )MIBG myocardial scintigraphy, brain natriuretic peptide (BNP), human atrial natriuretic peptide (hANP), and myocardial damage indices typified by troponin T and C-reactive protein (CRP) were collected. %Vp was lower in RURVP than in DDD (0.2% versus 95.7%, P = 0.00098). BNP, hANP, troponin T, and CRP did not differ significantly between the pacing modes. However, I-(123 )MIBG findings of patients with full ventricular pacing in DDD improved in RURVP. In contrast, among patients without full ventricular pacing in DDD, their I-(123 )MIBG findings did not differ significantly between the pacing modes. In SND patients with normal cardiac function and intact atrioventricular conduction, the reduction of %Vp in RURVP was due to the reduction of ineffective pacing and fusion pacing in DDD. Therefore, these 2 types of pacing do not affect cardiac pump function. |
13,484 | Stroke and bleeding risk assessment in atrial fibrillation: when, how, and why? | Decision making with regard to thromboprophylaxis should be based upon the absolute risks of stroke/thromboembolism and bleeding and the net clinical benefit for a given patient. As a consequence, a crucial part of atrial fibrillation (AF) management requires the appropriate use of thromboprophylaxis, and the assessment of stroke as well as bleeding risk can help inform management decisions by clinicians. The objective of this review article is to provide an overview of stroke and bleeding risk assessment in AF. There would be particular emphasis on when, how, and why to use these risk stratification schemes, with a specific focus on the CHADS2 [congestive heart failure, hypertension, age, diabetes, stroke (doubled)], CHA2DS2-VASc [congestive heart failure or left ventricular dysfunction, hypertension, age ≥ 75 (doubled), diabetes, stroke (doubled)-vascular disease, age 65-74 and sex category (female)], and HAS-BLED [hypertension (i.e. uncontrolled blood pressure), abnormal renal/liver function, stroke, bleeding history or predisposition, labile INR (if on warfarin), elderly (e.g. age >65, frail condition), drugs (e.g. aspirin, NSAIDs)/alcohol concomitantly] risk scores. |
13,485 | Acute hepatic failure following intravenous amiodarone. | A 73-year-old gentleman presented to the hospital after an episode of loss of consciousness. He had a defibrillator in situ, which on interrogation was found to have fired for an episode of ventricular fibrillation. As an inpatient he developed frequent episodes of self-terminating ventricular tachycardia, treated initially with oral amiodarone. A 24 h amiodarone infusion was started on day 3 of admission, following which the patient developed hyperventilation. Investigations revealed that this was secondary to acute hepatic and renal failure, requiring haemofiltration on the intensive care unit. Cessation of amiodarone was associated with normalisation of liver function over 48 h. The patient had normal blood and jugular venous pressures throughout days 1-4 of admission. We discuss the role of amiodarone as the predominant factor in the deterioration of this patient's liver function, versus the differential diagnosis of ischaemia-induced hepatotoxicity, citing recent research regarding this subject. |
13,486 | Hypothermia ameliorates gastrointestinal ischemic injury sustained in a porcine cardiac arrest model. | During cardiac arrest, the gastrointestinal tract is sensitive to ischemia. Protection of the gastrointestinal tract is a critical factor in determining prognosis following cardiopulmonary resuscitation (CPR). This study seeks to determine the extent of gastrointestinal tract injury and the potential protective effect of inducing hypothermia following a porcine cardiac arrest model and CPR.</AbstractText>Ventricular fibrillation was induced by programmed electrical stimulation in 16 male domestic pigs (n = 8 per group). Four minutes after ventricular fibrillation, CPR was performed. Pigs that successfully restored spontaneous circulation then received intravenous infusions of saline at either 4°C or room temperature to produce hypothermic and control conditions respectively. Serum diamine oxidase and gastrointestinal adenosine triphosphate enzyme activity were determined and histopathology of the gastrointestinal tract was performed by light microscopy and electron microscopy.</AbstractText>Significant injury of the gastrointestinal tract after CPR was found. Na(+)-K(+) and Ca(2+) adenosine triphosphate enzyme activity in the gastric tissue were significantly high in animals receiving hypothermia treatment compared to controls. Hypothermia also significantly reduced serum diamine oxidase after CPR compared to the control group. Moreover, severe injury sustained by the gastrointestinal tissue was significantly ameliorated under hypothermic conditions compared to controls.</AbstractText>Gastrointestinal injury and abnormal energy metabolism are strikingly evident following CPR. Hypothermia, which is induced by an infusion of 4°C saline, can rapidly reduce internal body temperature, improve energy metabolism, and ameliorate injury to the gastrointestinal mucosa after CPR.</AbstractText> |
13,487 | How should I treat a perimembranous interventricular defect following aortic valve replacement surgery? | A 73-year-old man was admitted to our Institute for repeated episodes of congestive heart failure. The patient was affected by arterial hypertension, dyslipidaemia, severe chronic obstructive pulmonary disease, and recurrent atrial fibrillation. Two months earlier he had undergone aortic valve replacement with a biological prosthesis for severe stenosis. Echocardiography showed a left-to-right shunt localised in the left ventricular outflow tract, normal morphology and function of the aortic valve prosthesis, and a hyperkinetic left ventricle.</AbstractText>Physical examination, electrocardiography, transthoracic and transoesophageal echocardiography, right heart catheterisation, left ventricular angiography.</AbstractText>Post-surgical perimembranous interventricular defect with a clinically significant left-to-right shunt.</AbstractText>Percutaneous closure with a ventricular septal defect occluder.</AbstractText> |
13,488 | Clinical features and prognosis in Chinese patients with acute fulminant myocarditis. | There is still a lack of large-scale studies focusing on acute fulminant myocarditis (AFM) and knowledge of this disease is unimpressive. To better understand the clinical features of AFM and improve the diagnosis and treatment of this disease, we analysed the data of consecutive Chinese AFM patients admitted to our department.</AbstractText>This retrospective observational study analysed the data of 40 patients with a diagnosis of AFM admitted to our hospital between January 2003 and March 2010.</AbstractText>The mean age of patients was 28.5 +/- 18.4 years and 70% of patients were females. 90.0% of patients had a short viral prodrome, 77.5% had cardiogenic shock and 35.0% had multiple organ failure, especially hepatic dysfunction. The most common manifestations in ECG were low voltage in the limb leads (87.5%) and sinus tachycardia (75%). Myocardial infarctions like ECG changes were not uncommon. Left ventricular ejection fraction (LVEF) was significantly reduced (25.3 +/- 7.5%), but the left cardiac sizes were normal. More than 90% of the patients were treated with glucocorticoids. 5.0% needed an intra-aortic balloon pump (IABP), and 35.0% were treated with bi-level positive airway pressure (BiPAP). In all, 39 (95.0%) patients were discharged alive and one man died from ventricular fibrillation. LVEF and left cardiac chambers at follow-up did not change as compared with discharge. No death, new onset heart failure or arrhythmias occurred during the follow-up.</AbstractText>This study describes the clinical features of Chinese AFM patients. The short- and mid-term prognosis of AFM is good. AFM patients may benefit from a treatment with glucocorticoids.</AbstractText> |
13,489 | Impact of antecedent hypertension on outcomes in patients hospitalized with severe forms of acute heart failure. | Even though several studies described a positive influence of elevated initial blood pressure on the outcome in acute heart failure (AHF), data specifically addressed to a population with severe AHF associated with antecedent hypertension, regardless of admission blood pressure values, are missing.</AbstractText>From the 4153 consecutive patients enrolled in the Czech AHF registry we selected 1343 patients who suffered from pulmonary oedema or cardiogenic shock and compared them according to the presence of antecedent hypertension. Demographic, clinical, laboratory, treatment profiles and mortality rates were assessed and predictors of short- and long-term outcome were identified. Patients with antecedent hypertension (n = 1053, 78%) were older (P < 0.001), more often women (P = 0.001), having more co-morbidities and a worse laboratory profile. A trend for worse survival of hypertensive patients was observed when compared to a non-hypertensive cohort (1-, 2-, 3-year survival 70.0, 61.5, 55.5% vs. 72.6, 68.2, 64.0%, P = 0.062). Age and creatinine levels were independently associated with mortality during the whole follow-up period (P < 0.001). Low left ventricular ejection fraction, need of mechanical ventilation, inotropic and vasopressor support, were adversely related to in-hospital mortality (P < 0.001). On the other hand, presence of initial tachycardia improved short-term outcome (P = 0.007). Long-term survival was worsened by initial atrial fibrillation (P = 0.036) and anaemia (P < 0.001) while the presence of de-novo AHF improved it (P = 0.009).</AbstractText>Long-term antecedent hypertension is not significantly correlated with mortality after an episode of severe AHF, but probably still participates in vascular and end-organ damage. Survival of these patients is determined by other associated co-morbidities.</AbstractText> |
13,490 | Congestive heart failure effects on atrial fibroblast phenotype: differences between freshly-isolated and cultured cells. | Fibroblasts are important in the atrial fibrillation (AF) substrate resulting from congestive heart failure (CHF). We previously noted changes in in vivo indices of fibroblast function in a CHF dog model, but could not detect changes in isolated cells. This study assessed CHF-induced changes in the phenotype of fibroblasts freshly isolated from control versus CHF dogs, and examined effects of cell culture on these differences.</AbstractText><AbstractText Label="METHODS/RESULTS" NlmCategory="RESULTS">Left-atrial fibroblasts were isolated from control and CHF dogs (ventricular tachypacing 240 bpm × 2 weeks). Freshly-isolated fibroblasts were compared to fibroblasts in primary culture. Extracellular-matrix (ECM) gene-expression was assessed by qPCR, protein by Western blot, fibroblast morphology with immunocytochemistry, and K(+)-current with patch-clamp. Freshly-isolated CHF fibroblasts had increased expression-levels of collagen-1 (10-fold), collagen-3 (5-fold), and fibronectin-1 (3-fold) vs. control, along with increased cell diameter (13.4 ± 0.4 µm vs control 8.4 ± 0.3 µm) and cell spreading (shape factor 0.81 ± 0.02 vs. control 0.87 ± 0.02), consistent with an activated phenotype. Freshly-isolated control fibroblasts displayed robust tetraethylammonium (TEA)-sensitive K(+)-currents that were strongly downregulated in CHF. The TEA-sensitive K(+)-current differences between control and CHF fibroblasts were attenuated after 2-day culture and eliminated after 7 days. Similarly, cell-culture eliminated the ECM protein-expression and shape differences between control and CHF fibroblasts.</AbstractText>Freshly-isolated CHF and control atrial fibroblasts display distinct ECM-gene and morphological differences consistent with in vivo pathology. Culture for as little as 48 hours activates fibroblasts and obscures the effects of CHF. These results demonstrate potentially-important atrial-fibroblast phenotype changes in CHF and emphasize the need for caution in relating properties of cultured fibroblasts to in vivo systems.</AbstractText> |
13,491 | ECG marker of adverse electrical remodeling post-myocardial infarction predicts outcomes in MADIT II study. | Post-myocardial infarction (MI) structural remodeling is characterized by left ventricular dilatation, fibrosis, and hypertrophy of the non-infarcted myocardium.</AbstractText>The goal of our study was to quantify post-MI electrical remodeling by measuring the sum absolute QRST integral (SAI QRST). We hypothesized that adverse electrical remodeling predicts outcomes in MADIT II study participants.</AbstractText>Baseline orthogonal ECGs of 750 MADIT II study participants (448 [59.7%] ICD arm) were analyzed. SAI QRST was measured as the arithmetic sum of absolute QRST integrals over all three orthogonal ECG leads. The primary endpoint was defined as sudden cardiac death (SCD) or sustained ventricular tachycardia (VT)/ventricular fibrillation (VF) with appropriate ICD therapies. All-cause mortality served as a secondary endpoint.</AbstractText>Adverse electrical remodeling in post-MI patients was characterized by wide QRS, increased magnitudes of spatial QRS and T vectors, J-point deviation, and QTc prolongation. In multivariable Cox regression analysis after adjustment for age, QRS duration, atrial fibrillation, New York Heart Association heart failure class and blood urea nitrogen, SAI QRST predicted SCD/VT/VF (HR 1.33 per 100 mV*ms (95%CI 1.11-1.59); P = 0.002), and all-cause death (HR 1.27 per 100 mV*ms (95%CI 1.03-1.55), P = 0.022) in both arms. No interaction with therapy arm and bundle branch block (BBB) status was found.</AbstractText>In MADIT II patients, increased SAI QRST is associated with increased risk of sustained VT/VF with appropriate ICD therapies and all-cause death in both ICD and in conventional medical therapy arms, and in patients with and without BBB. Further studies of SAI QRST are warranted.</AbstractText> |
13,492 | Intraoperative defibrillation threshold testing and postoperative long-term efficacy of cardioverter-defibrillator implantation. | The aim of this study was to determine the defibrillation threshold (DFT) of implantable cardioverter-defibrillators (ICDs) and outcomes of treatment. Sixty-four patients received cardioverter-defibrillator implantation. During implantation, the DFT was determined by the defibrillation safety margin (DSM). All patients were followed up for 12-48 months after the implantation. The overall DFT was 14.27±2.56 J and the DSM was 18.40±1.89 J. Malignant ventricular arrhythmias occurred in 42 patients following cardioverter-defibrillator implantation including 500 episodes of non-sustained ventricular tachycardia (VT) and 289 episodes of persistent VT. VT was treated using antitachycardia pacing (ATP); 265 episodes were treated successfully by a single ATP treatment (91.69%) and 12 episodes were treated successfully by two ATP treatments (4.15%). Twelve episodes were converted by low-energy electrical cardioversion (4.15%). A total of 175 ventricular fibrillation (VF) episodes were identified, of which 18 episodes automatically terminated prior to treatment. In total, 146 episodes were converted by a single cardioversion with a defibrillation energy of 13.21±2.58 J and 11 episodes were converted by two cardioversions with a defibrillation energy of 16.19±2.48 J. It is safe and feasible to determine the DFT by DSM measurement during cardioverterdefibrillator implantation. |
13,493 | Survival trends in pediatric in-hospital cardiac arrests: an analysis from Get With the Guidelines-Resuscitation. | Despite ongoing efforts to improve the quality of pediatric resuscitation, it remains unknown whether survival in children with in-hospital cardiac arrest has improved.</AbstractText>Between 2000 and 2009, we identified children (<18 years of age) with an in-hospital cardiac arrest at hospitals with >3 years of participation and >5 cases annually within the national Get With The Guidelines-Resuscitation registry. Multivariable logistic regression was used to examine temporal trends in survival to discharge. We also explored whether trends in survival were attributable to improvement in acute resuscitation or postresuscitation care and examined trends in neurological disability among survivors. Among 1031 children at 12 hospitals, the initial cardiac arrest rhythm was asystole and pulseless electrical activity in 874 children (84.8%) and ventricular fibrillation and pulseless ventricular tachycardia in 157 children (15.2%), with an increase in cardiac arrests due to pulseless electrical activity over time (P for trend <0.001). Risk-adjusted rates of survival to discharge increased from 14.3% in 2000 to 43.4% in 2009 (adjusted rate ratio per year, 1.08; 95% confidence interval, 1.01-1.16; P for trend=0.02). Improvement in survival was driven largely by an improvement in acute resuscitation survival (risk-adjusted rates: 42.9% in 2000, 81.2% in 2009; adjusted rate ratio per year: 1.04; 95% confidence interval, 1.01-1.08; P for trend=0.006). Moreover, survival trends were not accompanied by higher rates of neurological disability among survivors over time (unadjusted P for trend=0.32), suggesting an overall increase in the number of survivors without neurological disability over time.</AbstractText>Rates of survival to hospital discharge in children with in-hospital cardiac arrests have improved over the past decade without higher rates of neurological disability among survivors.</AbstractText> |
13,494 | Takotsubo syndrome: an underdiagnosed complication of 5-fluorouracil mimicking acute myocardial infarction. | Takotsubo syndrome (TTS)/cardiomyopathy is a syndrome that mimics acute myocardial infarction in the absence of coronary artery disease and is characterized by acute onset of chest pain, electrocardiographic abnormalities, and reversible left ventricular dysfunction. It is usually induced by emotional and physical stress. Fluorouracil is one of the most frequently used chemotherapy agents and a relatively common adverse reaction of fluorouracil is cardiotoxicity. Herein we describe a patient without a history of cardiovascular disorder who developed severe heart failure during infusion of fluorouracil for metastatic gastric cancer. Remarkably, the patient did not develop TTS during prior chemotherapy regimen, which also included fluorouracil. The patient's findings were consistent with the proposed TTS diagnostic criteria and coronary angiography was normal, without obstructive coronary artery disease. With supportive care, the patient's cardiac functions returned to normal. TTS is not a well known syndrome to clinicians and this condition appears to occur more frequently than previously thought. In addition to the presented case, a review of the clinical features and outcome of 10 reported cases of fluorouracil-induced TTS is presented. |
13,495 | Reversal of functional disorders by aspiration, expiration, and cough reflexes and their voluntary counterparts. | Agonal gasping provoked by asphyxia can save ~15% of mammals even from untreated ventricular fibrillation (VF), but it fails to revive infants with sudden infant death syndrome (SIDS). Our systematic study of airway reflexes in cats and other animals indicated that in addition to cough, there are two distinct airway reflexes that may contribute to auto-resuscitation. Gasp- and sniff-like spasmodic inspirations (SIs) can be elicited by nasopharyngeal stimulation, strongly activating the brainstem generator for inspiration, which is also involved in the control of gasping. This "aspiration reflex" (AspR) is characterized by SI without subsequent active expiration and can be elicited during agonal gasping, caused by brainstem trans-sections in cats. Stimulation of the larynx can activate the generator for expiration to evoke the expiration reflex (ExpR), manifesting with prompt expiration without preceding inspiration. Stimulation of the oropharynx and lower airways provokes the cough reflex (CR) which results from activating of both generators. The powerful potential of the AspR resembling auto-resuscitation by gasping can influence the control mechanisms of vital functions, mediating reversal of various functional disorders. The AspR in cats interrupted hypoxic apnea, laryngo- and bronchospasm, apneusis and even transient asphyxic coma, and can normalize various hypo- and hyper-functional disorders. Introduction of a nasogastric catheter evoked similar SIs in premature infants and interrupted hiccough attacks in adults. Coughing on demand can prevent anaphylactic shock and resuscitate the pertinent subject. Sniff representing nasal inspiratory pressure and maximal inspiratory and expiratory pressures (MIP and MEP) are voluntary counterparts of airway reflexes, and are useful for diagnosis and therapy of various cardio-respiratory and neuromuscular disorders. |
13,496 | Pro- and antiarrhythmic effects of ATP-sensitive potassium current activation on reentry during early afterdepolarization-mediated arrhythmias. | Under conditions promoting early afterdepolarizations (EADs), ventricular tissue can become bi-excitable, that is, capable of wave propagation mediated by either the Na current (INa) or the L-type calcium current (ICa,L), raising the possibility that ICa,L-mediated reentry may contribute to polymorphic ventricular tachycardia (PVT) and torsades de pointes. ATP-sensitive K current (IKATP) activation suppresses EADs, but the effects on ICa,L-mediated reentry are unknown.</AbstractText>To investigate the effects of IKATP activation on ICa,L-mediated reentry.</AbstractText>We performed optical voltage mapping in cultured neonatal rat ventricular myocyte monolayers exposed to BayK8644 and isoproterenol. The effects of pharmacologically activating IKATP with pinacidil were analyzed.</AbstractText>In 13 monolayers with anatomic ICa,L-mediated reentry around a central obstacle, pinacidil (50 μM) converted ICa,L-mediated reentry to INa-mediated reentry. In 33 monolayers with functional ICa,L-mediated reentry (spiral waves), pinacidil terminated reentry in 17, converted reentry into more complex INa-mediated reentry resembling fibrillation in 12, and had no effect in 4. In simulated 2-dimensional bi-excitable tissue in which ICa,L- and INa-mediated wave fronts coexisted, slow IKATP activation (over minutes) reliably terminated rotors but rapid IKATP activation (over seconds) often converted ICa,L-mediated reentry to INa-mediated reentry resembling fibrillation.</AbstractText>IKATP activation can have proarrhythmic effects on EAD-mediated arrhythmias if ICa,L-mediated reentry is present.</AbstractText>Published by Elsevier Inc.</CopyrightInformation> |
13,497 | Does induction of hypothermia improve outcomes after in-hospital cardiac arrest? | Hypothermia improves neurologic recovery compared to normothermia after resuscitation from out-of-hospital ventricular fibrillation, but may or may not be beneficial for patients resuscitated from in-hospital cardiac arrest. Therefore, we evaluated the effect of induced hypothermia in a large cohort of patients with in-hospital cardiac arrest.</AbstractText>Retrospective analysis of multi-center prospective cohort of patients with in-hospital cardiac arrest enrolled in an ongoing quality improvement project. Included were adults with a pulseless event in an in-patient hospital ward of a participating institution who achieved restoration of spontaneous circulation between 2000 and 2009. The exposure of interest was induced hypothermia. The primary outcome was survival to discharge. The secondary outcome was neurological status at discharge. Analyses evaluated all eligible patients; those with a shockable rhythm; or those with endotracheal tube inserted after resuscitation; and the effect of no hypothermia versus hypothermia (lowest temperature>32 °C but ≤34 °C) versus overcooled (≤32 °C). Associations were assessed using propensity score methods.</AbstractText>Included were 8316 patients with complete data, of whom 214 (2.6%) had hypothermia induced and 2521 (30%) survived to discharge. Of patients reported to receive hypothermia, only 40% were documented as achieving a temperature between 32 °C and 34 °C. Adjusted for known potential confounders using propensity score methods, induced hypothermia was associated with an odds ratio of survival of 0.90 (95% confidence interval: 0.65, 1.23; p-value=0.49) compared to no hypothermia. Induced hypothermia was associated with an odds ratio of neurologically-favorable survival of 0.93 (95% confidence interval: 0.65, 1.32; p-value=0.68) compared to no hypothermia. For patients with shockable first-recorded rhythm, induced hypothermia was associated with an odds ratio of survival of 1.43 (95% confidence interval: 0.68, 3.01; p-value=0.35) compared to no hypothermia.</AbstractText>Hypothermia is induced infrequently in patients resuscitated from in-hospital cardiac arrest with only 40% achieving target temperatures. Induced hypothermia was not associated with improved or worsened survival or neurologically-favorable survival. The lack of benefit in this population may reflect lack of effect, inefficient application of the intervention, or residual confounding. High-quality controlled studies are required to better characterize the effect of induced hypothermia in this population.</AbstractText>Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.</CopyrightInformation> |
13,498 | Evolving strategies for the use of spironolactone in cardiovascular disease. | The evolution of strategies for the use of spironolactone and its analogue, eplerenone, has, over the years, encompassed favourable modification of the natural history of symptomatic heart failure in subjects with subnormal left ventricular ejection fraction (LVEF), and mitigation of the risk of new-onset atrial fibrillation in mildly symptomatic systolic heart failure. Given the fact that these benefits might be attributable, at least in part, to mitigation of severity of diastolic dysfunction when the latter co-exists with subnormal LVEF, what needs to be explored is the possibility of similar benefits from the use of these agents in patients such as those with hypertension, and aortic valve stenosis, in whom left ventricular dysfunction is of the predominantly diastolic subtype. |
13,499 | High risk of severe cardiac adverse events in patients with mitochondrial m.3243A>G mutation. | To determine the long-term incidence of cardiac life-threatening complications and death in patients with the m.3243A>G mutation, and to identify cardiac prognostic factors.</AbstractText>We retrospectively included patients carrying the m.3243A>G mutation who were admitted to the Neuromuscular Disease Clinic of Pitié Salpêtrière Hospital between January 1992 and December 2010. We collected information relative to their yearly neurologic and cardiac investigations, their mutation load in blood, urine, and muscle at initial admission, and the occurrence of cardiac life-threatening adverse events and death during follow-up.</AbstractText>Forty-one patients (median age = 47 years [36-55 years], men = 13) were included, of whom 38 had clinical manifestations of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) and 3 were asymptomatic. One patient had a personal history of cardiac transplantation. Cardiac investigations displayed left ventricular hypertrophy, left ventricular dysfunction, or both abnormalities in 18 patients, along with Wolff-Parkinson-White syndrome in 7, conduction system disease in 4, and atrial fibrillation in 1. Over a median 5-year (3-9 years) follow-up period, 11 patients died, including 3 due to heart failure; 7 had life-threatening adverse events, including 6 hospitalizations for severe heart failure and 1 resuscitated cardiac arrest. By multivariate analysis, left ventricular hypertrophy was the only parameter independently associated with occurrence of cardiac adverse events.</AbstractText>Patients with the m.3243A>G mutation have a high incidence of cardiac death and life-threatening adverse events. Left ventricular hypertrophy was the only parameter independently associated with occurrence of these events.</AbstractText> |
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