While
verapamil has been proposed as a treatment for reducing electrophysiological remodeling due to
atrial fibrillation and atrial
tachyarrhythmias, no previous study has tested its effects in brady-tachy patients implanted with a dual-chamber pacemaker. Fourteen patients with frequent episodes of
atrial fibrillation (> or =2 episodes/month) in the setting of brady-tachy syndrome, implanted with a DDDR pacing system with extensive monitor function (Selection 900, Vitatron) were enrolled. Four months after implantation, they were randomly allocated to a 2-month period of treatment with
verapamil (240 mg/day) or to no treatment, followed by a crossover. The burden of atrial
tachyarrhythmias, the total number of hours spent in atrial
tachyarrhythmia and the mean number of hours per day spent in atrial
tachyarrhythmia were retrieved from diagnostic devices. The accuracy of atrial
tachyarrhythmias detection was confirmed independently by two observers. The main results showed that treatment with
verapamil was associated with a trend towards an higher percentage of atrial pacing in comparison with control (mean value+/-S.D.=63.2+/-29.9% vs. 57.3+/-30.6%, median value 53% vs. 49%, P value at Wilcoxon signed rank test=0.069), but without any significant reduction in atrial
tachyarrhythmia burden (4.5+/-11.8 vs. 3.3+/-9.1%) or total hours spent in atrial
tachyarrhythmia (65+/-161 vs. 48+/-131 h). Palpitation episodes were not significantly reduced by
verapamil treatment in comparison with control (10.3+/-7.8 vs. 6.1+/-6.5). In conclusion,
verapamil does not exert any beneficial effect on documented episodes of atrial
tachyarrhythmia in patients with brady-tachy syndrome implanted with a DDDR device. Moreover, this
drug was ineffective in reducing the number of palpitation episodes reported by the patient.