Particularities of dual chamber pacemaker therapy in patients after orthotopic heart transplantation.

Since August 1981, 33 orthotopic heart transplantations were performed in our hospital. Three of these patients (9%) had sinus bradycardias with rates as low as 30 beats/min; they were treated by implantation of a dual chamber pacemaker. These patients had two atria as a result of orthotopic heart transplantation, but only the donor atrium was suitable for positioning the atrial lead. In the postoperative period, some nonsurgical complications were observed in one patient who developed atrial fibrillation which we treated with drugs. A cyclosporin-evoked tremor produced several asystoles due to false inhibition by myopotential interference in the VVI mode. During an episode of acute rejection combined with renal insufficiency, loss of atrial and ventricular sensing occurred. The other patients showed no pacemaker-related complications. Our findings in this unique population of pacemaker patients are discussed.