Suppressing malignant arrhythmias rapidly with oral amiodarone loading

Serial ambulatory electrocardiographic monitoring was used to study the time course of the effects of oral amiodarone during a loading period in 50 patients with sustained ventricular tachycardia or ventricular fibrillation. Rapid, dramatic decreases in episodes of ventricular premature complexes, couplets, and nonsustained ventricular tachycardia were noted within 72 hours. Subsequent decreases in spontaneous arrhythmias, although statistically significant, were less marked. When judged by suppression of spontaneous ventricular arrhythmias noted during Holter monitoring, oral amiodarone given in loading doses has a rapid onset of action.