Efficacy of Flecainide in the Treatment of Catecholaminergic Polymorphic Ventricular Tachycardia: A Randomized Clinical Trial.

Importance: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a potentially lethal genetic arrhythmia syndrome characterized by polymorphic ventricular tachycardia with physical or emotional stress, for which current therapy with β-blockers is incompletely effective. Flecainide acetate directly suppresses sarcoplasmic reticulum calcium release-the cellular mechanism responsible for triggering ventricular arrhythmias in CPVT-but has never been assessed prospectively.

Objective: To determine whether flecainide dosed to therapeutic levels and added to β-blocker therapy is superior to β-blocker therapy alone for the prevention of exercise-induced arrhythmias in CPVT.

QRS Duration Changes in Patients with Single Ventricle Physiology: Birth to 10 Years.

Background: QRS prolongation may be a predictor of mortality in certain forms of congenital heart disease. Minimal data exist describing changes in QRS duration in patients with single ventricles (SVs). The goal was to describe changes in QRS duration in patients with SV and to determine if differences existed between single right ventricle (sRV) versus single left ventricle (sLV) patients.

Fascicular and nonfascicular left ventricular tachycardias in the young: an international multicenter study.

Introduction: The aim of this study was to evaluate the clinical presentation and outcomes of pediatric patients with ventricular tachycardia (VT) originating from left heart structures.

Methods And Results: This international multicenter retrospective study including 152 patients (age 10.0 ± 5.

QRS duration changes in patients with hypoplastic left heart syndrome undergoing hybrid palliation: prehybrid to post-Fontan.

Background: QRS prolongation has been shown to be a predictor of mortality in patients with certain forms of congenital heart disease. QRS changes have not been well described in patients with single ventricle physiology, particularly in those undergoing the hybrid procedure.

Objective: To describe QRS changes in a cohort of patients with hypoplastic left heart syndrome (HLHS) who underwent hybrid palliation and to evaluate if QRS duration is associated with mortality.

The study of antiarrhythmic medications in infancy (SAMIS): a multicenter, randomized controlled trial comparing the efficacy and safety of digoxin versus propranolol for prophylaxis of supraventricular tachycardia in infants.

Background: Supraventricular tachycardia (SVT) is one of the most common conditions requiring emergent cardiac care in children, yet its management has never been subjected to a randomized controlled clinical trial. The purpose of this study was to compare the efficacy and safety of the 2 most commonly used medications for antiarrhythmic prophylaxis of SVT in infants: digoxin and propranolol.

Methods And Results: This was a randomized, double-blind, multicenter study of infants <4 months with SVT (atrioventricular reciprocating tachycardia or atrioventricular nodal reentrant tachycardia), excluding Wolff-Parkinson-White, comparing digoxin with propranolol.