[Verapamil in the cardioversion of atrial fibrillation. Clinical study]

Abstract

Background: Prolonged periods of atrial fibrillation (AF) or high frequency atrial pacing lead to a significant shortening of atrial refractory periods. This time-dependent electric remodelling is reduced significantly by the administration of verapamil.

Methods: The present series consists of 24 patients all suffering from atrial fibrillation (33% acute AF and 66% chronic recurrent AF) admitted to our Cardiology Department (Rome University). Group G1 (13 patients) received i.v. verapamil (50 mg in 500 cc saline solution at 40 ml/hr). Group G2 (11 patients) received amiodarone i.v. (300 mg in bolus form followed by the infusion of 900 mg in 500 cc 5% glucosate solution, 33 ml/hr for 6 hours and subsequently 18 ml/hr). All patients received non-fractionated heparin i.v. at the same time.

Results: No statistically significant difference was observed in the percentage of pharmacological cardioversions in the two groups: G1=61% vs G2=54% p=0.94). The patients who were not cardioverted pharmacologically were done so electrically (external DC shock).

Conclusions: Albeit in this small population of patients verapamil proved to possess anti-arrhythmic effects on a par with that of standard amiodarone antiarrhythmic treatment. This antiarrhythmic potential of verapamil should be demonstrated in a broader randomised study.