Introduction: Sinus node dysfunction (SND) following orthotopic heart transplantation may lead to bradycardia, atrioventricular block, sick sinus syndrome, syncope, and death, with 6%-23% of patients requiring pacemakers.
Methods: Permanent pacemakers were placed in 5% of orthotopic heart transplants conducted at our institution from January 2002 to October 2008.
Results: THREE DIFFERENT IMPLANT TECHNIQUES WERE USED OVER THIS TIME: (1) dual-chamber pacing in the donor atrium and ventricle (A(D)-V(D)) (62.5%); (2) single lead in the donor atrium (A(D)) (12.5%); and (3) dual leads placed in both donor and recipient atrium (A(R)-A(D)) (25%). Using the percentage of paced histograms recorded in the device, heart rate variability for the types of lead placements were 14% for A(D)-V(D), 35% for A(D), and 97% for A(R)-A(D).
Discussion: The transplanted heart is characterized physiologically by autonomic denervation and chronotropic incompetence. Restoration of chronotropic competence by atrial pacing increases exercise duration and peak VO(2). Rate responsiveness can be achieved in this patient population with the placement of one lead in the remnant right atrium and one lead in the transplanted donor right atrium.
Keywords: Chronotropic incompetence; dual-atrial pacing; orthotopic heart transplantation; permanent pacemaker; sinus node dysfunction.