Loss of Sinus Activity after Long-Term Permanent VVI Pacing

In 183 out of 763 patients (24%) without sinus node dysfunction belonging to the atrioventricular conduction defect group, a spontaneous loss of sinus activity was detected after a 2–3 year follow-up period, following permanent VVI pacemaker implantation. Atrial fibrillation and/or atrial fibrillo-flutter may precede this final stage of loss of sinus activity.