Comparative study of intravenous amiodarone and procainamide in the treatment of atrial fibrillation of recent onset

Abstract

Aim: The aim of the present study was to compare the safety and efficacy of amiodarone and procainamide in the acute cardiology setting.

Methods: The study population consisted of 223 patients with symptomatic atrial fibrillation (AF). After administration of digoxin for ventricular rate control, all patients who failed to restore sinus rhythm (SR) were randomized into 2 groups: group A (113 patients) were administered 300 mg amiodarone intravenously over 30 min and, in case of failure to restore SR, amiodarone of 20 mg/kg/24 h was administered intravenously. Group B (110 patients) were intravenously administered a bolus dose of 1 gm procainamide, at an infusion rate 50/mg/min, and, in case of failure to restore SR, 2 mg/min for the next 24 h.

Results: The rate of cardioversion to SR was similar between amiodarone (81.4%) and procainamide (82.7%) (P=NS). Procainamide loading recorded faster cardioversion times than amiodarone loading (P=0.02), but there was no significant difference after that. Amiodarone caused a significant decrease on systolic blood pressure compared to procainamide for the first 18 h (P<0.001), and a significant decrease in the diastolic blood pressure for the first 6 h (P<0.001). Side-effects for either medication were sparse. The only real prognostic factor for successful cardioversion remains the size of left atrium.

Conclusion: Both drugs were equally effective in restoring SR, though procainamide acts quicker in the loading phase. Both medications are safe and side effects develop only in the maintenance phase.