Long-term results of amiodarone therapy

In order to assess the long-term efficacy of amiodarone, we followed 187 survivors of cardiac arrest and 316 patients with nonsustained or sustained ventricular tachycardia and compared the results of amiodarone therapy with the results of conventional therapy. All patients treated with amiodarone had failed to respond to one or more conventional agents. For survivors of cardiac arrest, survival of patients treated with amiodarone was equal to survival of patients treated with conventional agents. For patients with ventricular tachycardia, two-year survival was 91% in the conventional therapy group and 68% in the amiodarone group but incidence of sudden death was similar, probably reflecting increased non-sudden death due to advanced age and left ventricular dysfunction in the amiodarone-treated group. Side effects led to the discontinuation of amiodarone in approximately 25% of patients over a mean follow-up of 28 months. In a subgroup of patients who had demonstrated a proarrhythmic effect to Class I antiarrhythmic agents, amiodarone proved safe and effective. Amiodarone was well tolerated and effective therapy for atrial fibrillation in 59% of patients who had failed to respond to conventional agents. Thus, amiodarone is a useful option for patients with arrhythmias unresponsive to standard antiarrhythmic agents.