The Rate of Atrial Fibrillation Development in Patients with Cardiac Pacemakers

The rate of atrial fibrillation development was evaluated retrospectively in 167 patients (pts) who previously were in sinus rhythm, capable of restoring their own rhythm when the pacemaker was switched off, and had no history of atrial fibrillation. Cardic pacemakers were implanted because of sick sinus syndrome (SSS) in 79 patients while the other 88 patients had various indications to be paced (third-degree AV block 68, second-degree Mobitz type II AV block 12, bifascicular bundle block 5, hypersensitive carotid sinus syndrome 3). The modes of pacemakers were VVI in 129 pts, AAI in 6 pts and DDD in 32 pts. Atrial fibrillation developed in 43/167 (26 %) pts during follow-up. The number of pts who experienced atrial fibrillation during followup were 40/129 (31 %) for VVI pacing and 3/38 (8 %) for AAI/DDD pacing (p<0.05). Among patients with SSS, 26/179 (33 %) pts had atrial fibrillation while this number was 17/88 (19 %) among pts paced for other indications (p<0.05). In VVI pacing, 24/57 (42 %) pts with SSS had atrial fibrillation and in AAI/DDD pacing this number was 2/22 (9 %), and the difference was significant (p<0.05). Atrial fibrillation developed in 16/72 (22 %) pts with VVI pacing and 1/16 (6 %) pts with DDD pacing who were paced for indications other then SSS, disclosing again a significant difference (p<0.05). In conclusion, atrial fibrillation developed more frequently in pts with VVI pacemakers. We observed that the rate of atrial fibrillation development increases in pts with SSS. As the adverse effects of atrial fibrillation on quality of life and mortality rates are taken into consideration, we believe that it is rational to prefer pacing modes that provide AV synchrony especially in pts with SSS.