Activitrax AAIR pacing for sinus node dysfunction after orthotopic heart transplantation: an initial report.

Donor sinus node dysfunction is an uncommon event after orthotopic heart transplantation. In the past treatment of persistent symptomatic bradycardia in the setting of orthotopic heart transplantation has been accomplished by implantation of a single transvenous lead system with loss of atrioventricular synchrony and rate responsiveness or by implantation of a multiple transvenous lead system in which the multiple leads present a mechanical limitation to endomyocardial biopsy. To preserve atrioventricular synchrony, avoid the mechanical limitations of a ventricular lead at the time of routine biopsies, and maintain some degree of rate responsiveness during exercise, we elected to implant an activity-detecting pacing system with a single bipolar transvenous atrial lead in two of our orthotopic heart transplant recipients with persistent symptomatic donor sinus node dysfunction. This article details the techniques used and the results obtained in what we believe to be the first two implantations of this unique pacing system in orthotopic heart transplant recipients.