Mechanisms and management of arrhythmias in heart failure

Ventricular arrhythmias are a common problem in patients with heart failure and are an important cause of sudden death. Sustained ventricular arrhythmias are due either to reentry in an old infarct scar, bundle branch reentry, or the electrophysiologic abnormalities that accompany heart failure and hypertrophy. In animal models, ventricular hypertrophy that accompanies heart failure increases susceptibility to polymorphic ventricular tachycardias. Patients resuscitated from a sustained ventricular arrhythmia have a high risk of recurrence. Antiarrhythmic drug toxicity and inefficacy are increased in heart failure. Amiodarone or an implantable defibrillator are the first-line options, and have not been directly compared. Amiodarone appears to be the safest antiarrhythmic drug for treatment of nonsustained arrhythmias and atrial fibrillation. In one randomized trial, amiodarone improved survival in patients with advanced heart failure.