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 rand omized, single-blinded study in 19 patients with drug refractory AF, The st udy compared biatrial pacing with conventional right atrial (RA) pacing and a control period of inhibited pacing, The pacing modes utilized were DDD w ith 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 epi sodes and their duration were obtained from pacemaker Holter memory (Chorus RM ELA Medical). Comparison of the control period (n = 11) with either pac ing strategy showed a significant decrease in the total duration of AF (con trol 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 p eriod (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 wi th RA pace (n = 19), there was no significant difference in either the dura tion of AF (biatrial 16 +/- 26 days vs RA 19 +/- 31 days, p = 0.7) or the n umber of AF episodes (biatrial 56 +/- 91 vs RA 87 +/- 106, p = 0.34), In co nclusion, pacing (either type) at a base rate of 70 beats/min has an antifi brillatory effect when compared with inhibited pacing at 40 beats/min. No a dditional benefit of biatrial pacing over right atrial pacing was demonstra ted in this study, (C) 1999 by Excerpta Medica, Inc.