Effect of verapamil on prevention of atrial fibrillation in patients implanted with an implantable atrial defibrillator.

BACKGROUND: The role of verapamil in the prevention of atrial fibrillation (AF) in patients with recurrent AF is unknown. HYPOTHESIS: The aim of this study was to evaluate the effect of verapamil on the prevention of AF in patients implanted with an implantable atrial defibrillator (IAD). METHODS: The effects of verapamil (240 mg/day) on the total duration of AF, number of AF recurrences, and number of cardioversions were prospectively evaluated in a randomized, crossover fashion over an 8-week period in 11 patients (9 men, 2 women; mean age: 60 +/- 6 years) implanted with an IAD. RESULTS: Implantable atrial defibrillators successfully converted 13 of 14 (93%) spontaneous episodes of AF. There was no significant difference in the efficacy of cardioversion (86 vs. 100%, p = 0.8), the total duration of AF (173 +/- 198 vs. 270 +/- 241 h, p = 0.5), the number of AF episodes (8.5 +/- 9.0 vs. 9.3 +/- 10.2, p = 0.3), and the number of cardioversions (1.7 +/- 2.4 vs. 1.8 +/- 2.1 p = 0.7) with or without treatment with verapamil. CONCLUSIONS: The results of the present study suggest that treatment with verapamil has no significant effect on the prevention of AF in patients treated with an LAD.