Effectiveness of atrial antitachycardia pacing in the treatment of paroxysmal atrial fibrillation in patients with pacemakers

Introduction: The aim of this study was to assess the effectiveness of atrial antitachycardia pacing (ATP) in the conversion of atrial tachyarrhythmia episodes, and its impact in reducing arrhythmic burden. Methods: We performed a retrospective study in the pacing laboratory of a district hospital of 57 consecutive patients implanted with a dual chamber pacemaker, capable of performing atrial antitachycardia pacing, between 2005 and 2010. The patients were divided into two groups: ATP ON (n=24) and ATP OFF (n=33). The follow-up period was 15 months, with data being collected at three follow-up consultations: the first at three months after implantation, the second at nine months and the last at 15 months. In this period, there were 12 428 ATP therapies of atrial tachyarrhythmias. Results: Although there were no statistically significant differences, there was a trend in favor of the ATP ON group, the increase in arrhythmic burden being less marked in this group. The mean percentage of ventricular apical pacing was also significantly lower in this group, which was associated with a marginally significant reduction in arrhythmic burden (p=0.06). There was a significant positive correlation between changes in the percentage of ventricular pacing and changes in arrhythmic burden (r=0.417, p=0.02).