The usefulness of amiodarone in management of refractory supraventricular tachyarrhythmias.

The efficacy of amiodarone was evaluated in 85 patients with supraventricular tachycardia (SVT) refractory to several antiarrhythmic agents (mean 3.8 +/- 1.0). All but six patients had organic heart disease. Patients were followed for 19 months (range 2-60 months). Response to amiodarone treatment was considered excellent (no recurrence of SVT) in 22 of 52 patients with paroxysmal atrial fibrillation (PAF), in four of 13 patients with chronic atrial fibrillation (CAF), and in three of 15 patients with Wolff-Parkinson-White syndrome-related circus movement tachycardia (WPW-CMT). Response was improved (marked improvement in symptoms with partial suppression of SVT) in 22 patients with PAF, in seven patients with CAF, in 10 patients with WPW-CMT, and in four patients with atrioventricular nodal reentry tachycardia. Response was considered poor (insignificant or no suppression of SVT) in three patients with PAF, in one patient with CAF, and in one patient with WPW-CMT. Seven patients required discontinuation of amiodarone due to adverse effects. We conclude that amiodarone is efficacious and relatively safe for control of SVT refractory to conventional antiarrhythmic agents irrespective of the underlying electrophysiologic mechanism.