Antiarrhythmic drug therapy in congestive heart failure. Indications and complications

High-grade ventricular arrhythmias are common in congestive heart failure (CHF). However, antiarrhythmic drug therapy is indicated only for patients with symptomatic or hemodynamically significant sustained arrhythmias. Before such therapy is initiated, reversible causes of arrhythmias (eg, electrolyte imbalance, drug interactions and toxicity, decompensation of CHF, ongoing ischemia) should be sought out and corrected. Patients with poor ventricular function or a history of CHF should be hospitalized and monitored continuously during initiation and evaluation of antiarrhythmic therapy so that early detection of proarrhythmic response is possible. Therapy should be initiated with the smallest effective dose, which then is increased slowly to minimize the risk of side effects. Drug selection should be guided electrophysiologically or noninvasively, and empirical antiarrhythmic drug therapy must be avoided.