Randomized, double-blind trial of simultaneous right and left atrial epicardial pacing for prevention of post-open heart surgery atrial fibrillation.

BACKGROUND The purpose of this study was to assess simultaneous right and left atrial pacing as prophylaxis for postoperative atrial fibrillation. METHODS AND RESULTS In a double-blind, randomized fashion, 118 patients who underwent open heart surgery were assigned to right atrial pacing at 45 bpm (RA-AAI; n=39), right atrial triggered pacing at a rate of >/=85 bpm (RA-AAT; n=38), or simultaneous right and left atrial triggered pacing at a rate of >/=85 bpm (Bi-AAT; n=41). Holter monitoring was performed for 4. 8+/-1.4 days after surgery to assess for episodes of atrial fibrillation lasting >5 minutes. The prevalence of postoperative atrial fibrillation was significantly less in the patients randomized to biatrial AAT pacing when compared with the other 2 pacing regimens (P=0.02). An episode of atrial fibrillation occurred in 4 (10%) of 41 patients in the Bi-AAT group compared with 11 (28%) of 39 patients in the RA-AAI group (P=0.03 versus Bi-AAT) and 12 (32%) of 38 patients in the RA-AAT group (P=0.01 versus Bi-AAT). There was no difference in the occurrence of atrial fibrillation between the right atrial AAI and AAT groups (P=0.8). There was no significant difference among the 3 groups with regard to the number of postoperative hospital days (7.3+/-4.2 days), morbidity (5.1%), or mortality rate (2.5%). CONCLUSIONS Simultaneous right and left atrial triggered pacing is well tolerated and significantly reduces the prevalence of post-open heart surgery atrial fibrillation.