ULTRASTRUCTURE CHANGES ASSOCIATED WITH BRAIN-DEATH IN THE HUMAN DONORHEART

Electromicroscopic examinations were carried out on 30 myocardial biop sies taken from 22 human donor hearts immediately after excision (pres torage) or immediately before transplantation (poststorage). All elect ron micrographs were independently examined by two morphologists. Elev en structures were examined in each micrograph, and each structure was scored according to the degree of injury. A good interobserver correl ation was obtained in 84 % of the structures scored. In the prestorage left: ventricular biopsies (n = 11), approximately 20 % - 25 % showed moderate to severe ultrastructural injury. The ultrastructural injury observed in the poststorage left ventricular biopsies (n = 15) was no different from that in the prestorage group, particularly injury to t he sarcomere and mitochondria. A similar degree and pattern of injury was seen in the right ventricle (n = 4). There was no evidence that an ischemic storage period of less than 6 h increased the degree of inju ry seen. However, there was a higher incidence of moderate to severe i njury in those hearts excised from donors initially dependent on high inotropic support.