Does amiodarone reduce the incidence of arrhythmia compared to verapamil in patients with hypertrophic cardiomyopathy complicated by refractory arrhythmias?
Amiodarone is highly effective at suppressing refractory ventricular and atrial arrhythmias in patients with hypertrophic cardiomyopathy, whereas verapamil is ineffective.
The antiarrhythmic effects of amiodarone and verapamil were compared in 19 patients with hypertrophic cardiomyopathy complicated by refractory arrhythmias. While verapamil did not reduce the incidence of arrhythmia, amiodarone abolished ventricular tachycardia in 10 of 13 patients and significantly reduced the number of ventricular extrasystoles. In addition, sinus rhythm was restored by amiodarone in three of five patients with longstanding atrial fibrillation.
McKenna et al. (1981) studied this question.