LONG-TERM FOLLOW-UP OF HEART-TRANSPLANT RECIPIENTS REQUIRING PERMANENT PACEMAKERS

Background: Permanent pacemaker implantation after heart transplantati on is contentious. Indications for these devices in this population ar e uncertain. The goals of this project were to (1) analyze the time co urse of donor sinus node dysfunction and atrioventricular block after heart transplantation; (2) evaluate which selected parameters (donor a ge, ischemic time, heart rate before pacer insertion, and number of re jection episodes) might relate to persistent permanent pacing need, an d (3) assess pacemaker complications during follow-up. Methods: A retr ospective analysis of pacemaker implantations (22 cases) was performed in 286 consecutive heart transplantations performed between February 1984 and April 1994 at The Methodist Hospital and Baylor College of Me dicine, Houston, Texas. Results: Permanent pacemakers were inserted ea rly after transplantation in 19 patients (mean 24 days); 14 pacemakers were for sinus node dysfunction (bradycardia in five, sinus arrest wi th junctional escape in eight, and optimization of hemodynamics in one ). Symptomatic complete heart block prompted insertion late in two pat ients (3 and 47 months), and symptomatic sinus pause was the indicatio n for late insertion in one. Recipient mean age was 52.4 years, with m ean donor age 29.7 years in patients with pacemakers. By 3 months, 13 of 19 patients receiving pacemakers early (mean preinsertion heart rat e 58.3 beats/min) became pacer independent with subsequent mean intrin sic heart rate of 97 beats/min. Recipient or donor age, ischemic time, and rejection episodes did not appear related to long-term pacing nee d early or late after transplantation. Conclusions: Inferences from th ese observations include the fact that many patients with early sinus node dysfunction and bradycardia are not pacer dependent at 3 months. However, those with atrioventricular block early appear to require lon g-term pacing support. However, the possibility that more aggressive a nd long-term oral chronotropic medication use after transplantation wo uld obviate early permanent pacemaker need is not addressed. Finally, prospective clinical trials are necessary to precisely characterize be nefit of permanent pacemakers and define optimal pacing modes after he art transplantation.