Background: Bradycardia and sinus node dysfunction are common causes of early postoperative morbidity in orthotopic heart transplant recipients and frequently require the use of chronotropic drugs or permanent pacemakers. Several causes have been postulated, including surgical trauma to the sinus node and its blood supply. We sought to eliminate sinus node dysfunction and postoperative bradyarrhythmias by altering the orthotopic heart transplantation technique.
Methods and results: Seventy orthotopic heart transplant recipients underwent electrophysiological testing of sinus node function a mean of 9 +/- 3 days after surgery. Standard (atrial anastomosis) orthotopic heart transplantation was performed in 33 patients; total (bicaval anastomosis) heart transplantation was performed in 37 patients. Abnormalities of sinus node function were present in 14 of 33 patients (42%) undergoing standard orthotopic heart transplantation compared with 2 of 37 patients arrhythmia (5%) in whom total heart transplantation was performed (P < .005). The resting sinus heart rate of patients with a normal sinus rhythm was also significantly higher in the total heart transplantation group (90 +/- 12 versus 83 +/- 14 bpm, P < .05). Coronary angiography was performed before discharge in 63 patients. Eleven were found to have an abnormal sinoatrial nodal artery, and 7 of these patients also had evidence of sinus node dysfunction (P < .005).
Conclusions: Surgical trauma to the donor sinus node and/or its blood supply is a significant cause of sinus node dysfunction in the orthotopic heart transplant recipient. By use of a bicaval anastomotic technique, the incidence of and need for treatment of postoperative bradyarrhythmias can be significantly reduced.