Pacing requirements after orthotopic heart transplantation: incidence and related factors.

To assess the incidence of severe bradyarrhythmia and pacing requirements after orthotopic heart transplantation, as well as the possible causal mechanisms, we have reviewed our experience on 52 consecutive transplant patients. The overall incidence of bradyarrhythmia requiring pacing for at least 24 hours after transplantation was 27% (14 patients). The conditions of three of them required pacing for less than 1 week; the conditions of the other 11 patients (21%) required pacing for more than 1 week. Normal sinus rhythm resumed in all but four patients within 3 weeks; a permanent pacemaker was implanted in these four patients (7.6% of all 52 patients and 28% of patients requiring temporary pacing). Late complete heart block associated with acute rejection developed in two patients whose conditions required implantation of a permanent pacemaker. The age and sex of the recipient and donor were similar for patients with or without bradyarrhythmia. The percentage of patients with or without bradyarrhythmias taking amiodarone before transplantation (57% and 46%, respectively), total ischemic time (133 +/- 33 and 123 +/- 37 minutes, respectively), and cardiopulmonary bypass time (117 +/- 17 and 132 +/- 65 minutes, respectively) were not significantly different for either group of patients. The initial temperature of cardioplegic solution for organ storage and the preimplantation myocardial temperature were, however, significantly lower in patients whose conditions required pacing immediately after transplantation than in those whose conditions did not require pacing (5.3 +/- 1.7 degrees C versus 6.5 +/- 1.5 degrees C, p less than 0.05, and 3.9 +/- 1.6 degrees C versus 5.7 +/- 2.6 degrees C, p less than 0.01, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)