Randomized prospective pilot study of long-term dual-site atrial pacing for prevention of atrial fibrillation

Objective: To determine whether dual-site atrial pacing is feasible, safe, and effective. Design: We undertook a randomized prospective single- blind crossover study. Material and Methods: Nine patients with at least two episodes per month of symptomatic paroxysmal atrial fibrillation participated in a randomized crossover study involving three separate 3-month blocks of single-site atrial pacing, dual-site atrial pacing, and control (support- only) pacing. Results: Dual-site atrial pacing resulted in shorter P wave duration (81 ± 14 ms) than did single-site pacing (111 ± 12 ms) or control sinus rhythm (123 ± 9 ms) (P<0.0001) and in fewer premature atrial complexes on Holter monitoring (P = 0.06). The arrhythmia-free interval was longer with dual-site pacing (67 ± 17 days) than with single-site (62 ± 30 days) or support-only (49 ± 34 days) pacing (P = 0.10). This pilot study was not statistically powered to detect a difference between pacing modes. Conclusion: (1) Dual-site atrial pacing is feasible and safe; (2) it shortens the P wave duration and tends to decrease premature atrial complexes on Holter monitoring; (3) any atrial pacing tends to prolong the arrhythmia- free interval; and (4) this pilot study enrolled too few patients to determine whether a significant difference in pacing modes exists and supports the need for a larger study.