Design and rationale of a pragmatic randomized clinical trial of early dronedarone versus usual care to change and improve outcomes in persons with first-detected atrial fibrillation - the CHANGE AFIB study.

Background: While there are several completed clinical trials that address treatment strategies in patients with symptomatic and recurrent atrial fibrillation (AF), there are no randomized clinical trials that address first-line rhythm control of new-onset AF. Recent data suggest that early initiation of rhythm control within 1 year can improve outcomes.

Methods: In this open-label pragmatic clinical trial nested within the Get with The Guidelines Atrial Fibrillation registry, approximately 3,000 patients with first-detected AF will be enrolled at approximately 200 sites.

Racial Disparities in Ion Channelopathies and Inherited Cardiovascular Diseases Associated With Sudden Cardiac Death.

Cardiovascular disease (CVD) continues to be the most common cause of death worldwide, and cardiac arrhythmias account for approximately one half of these deaths. The morbidity and mortality from CVD have been reduced significantly over the past few decades; however, disparities in racial or ethnic populations still exist. This review is based on available literature to date and focuses on known cardiac channelopathies and other inherited disorders associated with sudden cardiac death in African American/Black subjects and the role of epigenetics in phenotypic manifestations of CVD, and illustrates existing disparities in treatment and outcomes.

Application of Electromechanical Window Negativity as an Arrhythmia Risk Correlate in Acquired Long QT Syndrome.

Long QT syndrome is a congenital or acquired condition associated with life-threatening cardiac arrhythmias. Risk stratification measures are paramount to providing life-saving therapy. We present a case of a 30-year-old man with syncope and polymorphic ventricular tachycardia from drug-induced QTc prolongation.

Cardiac resynchronization therapy: A comparative analysis of mortality in African Americans and Caucasians.

Background: Cardiac resynchronization therapy (CRT) is recommended in patients with heart failure, reduced left ventricular ejection fraction, and a prolonged QRS duration. African Americans are underrepresented in clinical trials and CRT is underutilized; consequently, the benefits and outcomes of CRT are not well-defined.

Methods: We evaluated 294 patients, determined survival using Kaplan-Meier analysis, and used Cox proportional hazards regression model to determine predictors of mortality.

Sinus Bradycardia in Habitual Cocaine Users.

Common physiological manifestations of cocaine are related to its adrenergic effects, due to inhibition of dopamine and norepinephrine uptake at the postsynaptic terminal. Few studies have documented bradycardia secondary to cocaine use, representing the antithesis of its adrenergic effects. We assessed the prevalence of sinus bradycardia (SB) in habitual cocaine users and postulated a mechanism for this effect.

Mortality in African-Americans Following Cardiac Resynchronization Therapy: A Single Center Experience.

Background: Cardiac resynchronization therapy (CRT) improves clinical outcomes and reduces mortality in heart failure patients who remain symptomatic despite optimal medical therapy. CRT trials have reported significant hemodynamic benefits, improvement in functional status, and reduced mortality and heart failure hospitalizations. However, African-American patient representation in these studies is limited thus the results may not be applicable to them.

Test-retest reliability of the electromyographic fatigue threshold for cycle ergometry.

Introduction: The purpose of this study was to determine the intersession reliability of the electromyographic fatigue threshold (EMGFT ) for cycle ergometry.

Methods: On separate occasions, 10 healthy, college-aged men performed an incremental test to voluntary exhaustion on a cycle ergometer. The EMG amplitude vs.

Biventricular paced QRS predictors of left ventricular lead locations in relation to mortality in cardiac resynchronization therapy.

Background: Left ventricular (LV) lead location during cardiac resynchronization therapy (CRT) has influenced mortality and heart failure events; however the biventricular paced QRS morphology has not been established as a predictor of LV lead location or mortality.

Methods: We evaluated the biventricular paced QRS morphology in 306 patients undergoing CRT in relation to specific anatomic locations. A logistic regression model and Kaplan-Meier survival estimates were used to determine predictors of LV lead location and survival.

Asymptomatic sinus bradycardia following bariatric surgery.

Approximately 121,000 bariatric surgical procedures are performed annually, and salutary effects include a reduction in cardiovascular morbidity and mortality, risk factor modification, and improvement in sympathovagal tone. There are anecdotal accounts of unexplained sinus bradycardia (SB) after significant weight loss but no systematic studies have been conducted. The purpose of this study was to determine the frequency of incident SB, its timing, and association with weight loss, clinical characteristics, and predictors.

Percutaneous pacemaker and implantable cardioverter-defibrillator lead extraction in 100 patients with intracardiac vegetations defined by transesophageal echocardiogram.

Objectives: We describe the feasibility, safety, and clinical outcomes of percutaneous lead extraction in patients at a tertiary care center who had intracardiac vegetations identified by transesophageal echocardiogram.

Background: Infection in the presence of intracardiac devices is a problem of considerable morbidity and mortality. Patients with intracardiac vegetations are at high risk for complications related to extraction and protracted clinical courses.

Axillary subpectoral approach for pacemaker or defibrillator implantation in patients with ipsilateral prepectoral infection and limited venous access.

Purpose: The prepectoral approach is the procedure of choice for pacemaker or defibrillator (device) implantation. Epicardial or transiliac approaches are reserved for patients in whom the pectoral approach is not feasible. We studied the viability of the axillary subpectoral approach for implanting devices in patients in whom the standard prepectoral approach was not feasible.

Clinical assessment of the risk for sudden cardiac death in patients with sickle cell anemia.

Background: Previous studies suggest that patients with sickle cell anemia (SCA) have an increased risk of sudden cardiac death; however, its etiology and mechanism are not well defined. Left ventricular hypertrophy (LVH), ventricular tachycardia (VT) and poor left ventricular systolic function are known risk factors for sudden cardiac death. An abnormal microvolt T-wave alternans (TWA) test is also a predictor of sudden cardiac death risk, but it has not been applied to this patient population.

Microvolt T-wave alternans and the risk of death or sustained ventricular arrhythmias in patients with left ventricular dysfunction.

Objectives: This study hypothesized that microvolt T-wave alternans (MTWA) improves selection of patients for implantable cardioverter-defibrillator (ICD) prophylaxis, especially by identifying patients who are not likely to benefit.

Background: Many patients with left ventricular dysfunction are now eligible for prophylactic ICDs, but most eligible patients do not benefit; MTWA testing has been proposed to improve patient selection.

Methods: Our study was conducted at 11 clinical centers in the U.

Microvolt T-wave alternans distinguishes between patients likely and patients not likely to benefit from implanted cardiac defibrillator therapy: a solution to the Multicenter Automatic Defibrillator Implantation Trial (MADIT) II conundrum.

Background: In 2003, the Centers for Medicaid and Medicare Services recommended QRS duration as a means to identify MADIT II-like patients suitable for implanted cardiac defibrillator (ICD) therapy. We compared the ability of microvolt T-wave alternans and QRS duration to identify groups at high and low risk of dying among heart failure patients who met MADIT II criteria for ICD prophylaxis.

Methods And Results: Patients with MADIT II characteristics and sinus rhythm had a microvolt T-wave alternans exercise test and a 12-lead ECG.