ULTRASTRUCTURAL FINDINGS IN CARDIAC TRANSPLANT RECIPIENTS

Ultrastructural findings in 350 endomyocardial biopsy specimens and 59 autopsy or explanted hearts from cardiac transplant recipients are re viewed. Myocyte degeneration can be readily distinguished from necrosi s by the technique described. Vascular changes of endothelial activati on, endothelial cell damage, and basement membrane reduplication can b e readily identified. In addition, the myofilament composition of isch emic hearts in patients with allograft coronary artery disease is dist inctive: There is a disproportionate loss of actin over myosin, giving a coarse appearance to the myofilaments. These changes are useful in further defining the morphologic features associated with rejection an d ischemia in cardiac transplant recipients.