Atrial fibrillation and embolic complications in paced patients

Atrial fibrillation (AF) and thromboembolism are discussed to be complications of the VVI mode. We reinvestigated the spontaneous ECG and the anamnesis of 246 pacemaker patients with the indications second and third degree atrioventricular block (AV block, n = lll), sick sinus syndrome (SSS, n = 101) and other indications (n = 34), all had shown sinus rhythm at implantation. The mean implantation time was 63 +/- 45 months (203 VVI and 43 dual chamber pacemakers).

(1) Atrial fibrillation was found in 63 patients (26%). Only one of them had a DDD pacemaker inserted, the implantation time of dual chamber devices being shorter, however, (2) The incidence of AF in patients with SSS (37%) was significantly higher (P less than 0.01) than in patients with AV block (19%). (3) Three patients suffered from strokes or transitory ischemic attacks in the follow-up, only one of them had AF at control.

Our results confirm that VVI stimulation favors AF long-term which is most likely due to irritation of the atrial rhythm by retrograde conduction. In our patients the incidence of thromboembolic complications was not higher in the group of patients with AF. However, from this study in surviving patients, we cannot exclude that we lost some patients due to severe stroke.