Right ventricular dysfunction after cardiac transplantation: Primarily related to status of donor heart

Background. It is unclear whether right ventricular dysfunction after trans plantation is due to donor brain death-related myocardial injury or recipie nt pulmonary hypertension. Methods. A canine donor model of brain death and a monocrotaline pyrrole-in duced chronic pulmonary hypertension recipient model were established, and used for 30 orthotopic bicaval cardiac transplantations divided into three groups: Controls (group A, normal donor/recipient), group B (brain-dead don ors/normal recipient), and group C (normal donor/recipients with pulmonary hypertension). Right ventricular function was measured before transplant an d brain death, 4 hours after brain death, and after transplant (1 hour off bypass) by load-independent means plotting stroke work versus end-diastolic volume during caval occlusion. Right ventricular total power and pulmonary vascular impedance were determined by Fourier analysis. Results. In comparison to the control group right ventricular preload-recru itable stroke work and total power decreased significantly after brain deat h and transplant in group B (from 22.7 x 10(3) erg (+/-1.2) at baseline to 15.6 x 103 (+/-0.9) after brain death and to 11.3 x 103 (+/-0.9) after tran splant). In group C there was a significant increase in pulmonary artery pr essure, impedance, right ventricular preload-recruitable stroke work, total power after transplant. Conclusions. Normal donor hearts adapt acutely to the recipient's elevated pulmonary vascular resistance by increasing right ventricular power output and contractility. Brain death caused significant right ventricular dysfunc tion and power loss, which further deteriorated after graft preservation an d transplantation. The effects of donor brain death on myocardial function contribute to right ventricular dysfunction after cardiac transplantation.