THE COMBINED EFFECTS OF BRAIN-DEATH AND CARDIAC GRAFT PRESERVATION ONCARDIOPULMONARY HEMODYNAMICS AND FUNCTION BEFORE AND AFTER SUBSEQUENTHEART-TRANSPLANTATION

Background: The combined effects of brain death and graft preservation on right and left ventricular function and on pulmonary hemodynamics after subsequent heart transplantation have not been previously studie d. Methods: Fifty-seven dogs (25.5 +/- 0.3 kg) were divided into three groups and underwent a total of 20 brain death experiments and 16 ort hotopic complete atrioventricular transplantations with use of a valid ated brain death organ donor model, hypothermic heart preservation, an d right and left ventricular functional analysis (preload-independent recruitable stroke work, Fourier analysis). In the first group, change s in cardiopulmonary function were assessed over a period of 6 to 7 ho urs after brain death. In the second group, the hearts were procured f rom a donor with brain death and immediately transplanted whereas in t he third group cardiac graft preservation for a period of 4 hours foll owed harvest from a donor with brain death before heart transplantatio n and assessment of heart transplant function. Results: After brain de ath alone, a significant increase in right and left ventricular end-di astolic pressures and a decrease in systemic and pulmonary resistance and pulmonary impedance occurred. Furthermore, right and left ventricu lar function decreased significantly by 35% and 19%, respectively, and subsequent transplantation did not cause further cardiac dysfunction. Preservation in combination with brain death led to further significa nt decreases in right ventricular function after subsequent transplant ation compared with brain death alone, necessitating the use of dopami ne to wean four animals from cardiopulmonary bypass. Conclusion: Brain death causes a significant loss of right and left ventricular functio n. These injuries are greater in the right ventricle and may contribut e to early right ventricular failure after transplantation. Brain deat h and cardiac graft preservation have significantly additive deleterio us effects on right ventricular function after transplantation.