BACKGROUND Calcium-lowering drugs seem to be able to reduce the recurrences of atrial fibrillation (AF) after cardioversion by preventing electrical remodeling of atrial cells. The aim of our study was to prospectively evaluate the efficacy of short-term verapamil therapy associated with propafenone or amiodarone in reducing recurrences of AF after low energy intracardiac cardioversion. METHODS Eighty-two patients with chronic AF (mean duration 6.1 months, range 1-96 months) underwent low energy intracardiac cardioversion. Forty-one patients (Group A) were instructed to suspend antiarrhythmic therapy 48 hours before the procedure (only chronic amiodarone was allowed). The subsequent 41 patients (Group B), in addition to previous prescriptions, had to take verapamil (120 mg twice daily) for 3 days before low energy intracardiac cardioversion and for 7 days after cardioversion. A right atrium-coronary sinus or right atrium-left pulmonary artery electrode configuration was indifferently utilized. Propafenone (450-900 mg daily) or amiodarone (200 mg daily) was prescribed to all patients after cardioversion. RESULTS Sinus rhythm was acutely restored in 80 patients (97.6%): the mean number of shocks delivered was 2.3 (range 1-5); the mean energy required was 10.5 J (range 7.2-19.8 J). No statistically significant differences were found between the right atrium-coronary sinus vs right atrium-left pulmonary artery electrode configuration regarding the energy required and the number of shocks delivered. Group A and Group B showed the same number of AF recurrences at the first month of follow-up. CONCLUSIONS In our study, short-term verapamil treatment associated with propafenone or amiodarone seems to be useless for the prevention of recurrent AF after low energy intracardiac cardioversion.