Evaluation of biatrial pacing, right atrial pacing, and no pacing in patients with drug refractory atrial fibrillation

It has been suggested biatrial pacing may prevent the recurrence of atrial fibrillation (AF). To further evaluate this hypothesis, we performed a randomized, single-blinded study in 19 patients with drug refractory AF. The study compared biatrial pacing with conventional right atrial (RA) pacing and a control period of inhibited pacing. The pacing modes utilized were DDD with a base rate of 70 beats/min for biatrial and RA pace (with and without biatrial resynchronization, respectively) and 40 beats/min for the control period. The duration of each pacing mode was 3 months. The number of AF episodes and their duration were obtained from pacemaker Holter memory (Chorus RM ELA Medical). Comparison of the control period (n = 11) with either pacing strategy showed a significant decrease in the total duration of AF (control 27 ± 35 days, biatrial 8 ± 15 days p = 0.02, RA 11 ± 27 days p = 0.04). However, there was no effect on the number of AF episodes (control 79 ± 108, biatrial 36 ± 75 p = 0.32, RA 41 ± 80 p = 0.11). The total percentage of atrial pacing also significantly increased when the control period (6 ± 9%) was compared with both RA pace (62 ± 33%, p = 0.008) and biatrial pace (63 ± 31, p = 0.003). When biatrial pacing was compared with RA pace (n = 19), there was no significant difference in either the duration of AF (biatrial 16 ± 26 days vs RA 19 ± 31 days, p = 0.7) or the number of AF episodes (biatrial 56 ± 91 vs RA 87 ± 106, p = 0.34). In conclusion, pacing (either type) at a base rate of 70 beats/min has an antifibrillatory effect when compared with inhibited pacing at 40 beats/min. No additional benefit of biatrial pacing over right atrial pacing was demonstrated in this study.