Atrial Fibrillation After DDDR Pacemaker Implantation

INTRODUCTION: Newer implantable pulse generators have data storage capabilities that permit detection of multiple episodes of atrial fibrillation (AF). This study evaluated the clinical predictors and time course of AF development in a general pacemaker population. METHODS AND RESULTS: Patients (n = 231) received DDDR pacemakers with features that permit detection and storage of information about the date, time of onset, and duration of multiple, sequential episodes of AF. Patients were followed for 718+/-383 days. Time to first occurrence of AF, interval between first and second episode of AF, and total AF burden were determined at each follow-up visit. AF occurred more often in patients (68%) with sinus node disease than in patients with AV block (37%; P < 0.001). Time to first occurrence of AF was 21.2 days (95% confidence interval CI 14.7 to 30.6 days) after pacemaker implantation. AF burden initially decreased significantly in patients (0.8 hours/day, 95% CI 0.7 to 0.9 at 8 weeks after implant vs 0.6 hours/day, 95% CI 0.4 to 0.8 at 12 months after implant; P = 0.005) but then increased significantly during long-term follow-up (2.0 hours/day, 95% CI 1.0 to 3.7 at 48 months after implant; P = 0.008). The long-term increase in AF burden was seen predominantly in patients with sinus node disease. A prior history of AF and the duration of follow-up were independent predictors of AF occurrence. CONCLUSION: AF develops frequently after dual-chamber pacemaker implantation. AF burden increases progressively over the long term.