Analysis of incidence of atrial fibrillation after implantation of VVI pacemaker--long-term observation of 154 patients.

Incidence of occurrence of atrial fibrillation (Af) after implantation of VVI was examined and the possible mechanism was explored. Eighty cases of atrioentricular block (AVB) and 74 cases of sick sinus syndrome (SSS) were studied and followed up for 1-14 years after implantation of VVI. The endpoint was the occurrence of permanent Af. The results showed that the incidence of Af among the 154 patients was 14.3% (22/154). And the incidence was 2.5% among patients with AVB (2/80), and 27% among patients with SSS (20/74). Significant significance was found between patients with AVB and those with SSS (P < 0.01). Among the patients with SSS, the incidence was 33.3% (9/27) in type I, 38.1% (8/21) in type III and 11.5% (3/26) in type II. Significant differences were revealed among patients with I, III and II type SSS (P < 0.05). It is concluded that retrograde conduction of pure ventricular pacing may play the chief role of occurrence of Af.