[A comparison between amiodarone and disopyramide in a delayed-release formulation in the prevention of recurrences of symptomatic atrial fibrillation]

Abstract

In order to compare the efficacy in preventing recurrencies of symptomatic atrial fibrillation of amiodarone (A.) and slow release disopyramide (D.RET.), 76 consecutive patients with recent onset atrial fibrillation (1 to 24 hrs.) were enrolled. In 20 (26%) conversion to sinus rhythm was obtained by electrical cardioversion, and in 56 (74%) by oral quinidine loading. Forty-one patients (group A) were assigned at random to treatment with D.RET. (250 mg twice daily) and 35 patients (group B) to amiodarone treatment (1200 mg daily for 10 days, and subsequently 200 mg daily). The two groups were similar as to age, sex and cardiac pathology. Patients were followed as to clinical condition, standard and dynamic ECG after one and three months and every three months subsequently for an average of 13.2 months (group A) and 14.1 months (group B). Six group A patients (14%) were excluded from follow-up on account of side effects which arose during the first week of treatment. Crises of symptomatic atrial fibrillation occurred in 20 patients of group A (57%) and in 11 (32%) group patients; this difference is statistically significant (p less than 0.05). Four (10%) group A patients stopped taking the drug due to side effects of an anticholinergic type, and three (8.5%) patients developed hyperthyroidism during follow-up. The authors therefore come to the conclusion that amiodarone is more effective than slow-release disopyramide in preventing recurrencies of atrial fibrillation; besides untoward side effects are less frequent with amiodarone.