Antiarrhythmic therapy in patients with congestive heart failure.

Current information suggests that in patients with congestive heart failure (CHF) who have asymptomatic ventricular arrhythmias, coronary artery disease (dilated ischemic cardiomyopathy), and a positive signal-averaged electrocardiogram, electrophysiologic studies are useful for stratifying risk and guiding therapy. Therapy with amiodarone hydrochloride (Cordarone) appears to improve survival in patients after myocardial infarction. In CHF patients with asymptomatic ventricular arrhythmias and dilated nonischemic cardiomyopathy, electrophysiologic studies are of little value in risk stratification because of their low yield of sustained monomorphic tachycardias. There is little evidence that therapy with conventional antiarrhythmic agents improves survival. Although amiodarone can suppress ventricular ectopic beats, no trial yet conducted has detected an effect on mortality. Randomized, controlled trials with low-dose amiodarone are needed for more definitive information. Most symptomatic patients should undergo electrophysiologic testing and receive guided therapy, either with antiarrhythmic drugs or with an implantable cardioverter-defibrillator.