Ultrastructural alterations in the myocardium of patients with sickle cell anemia.

Endomyocardial biopsies of patients with sickle cell anemia (SCA) were examined ultrastructurally. Myocardial fibers of patients revealed prominent degenerative changes such as nuclear chromatin condensation, myofibrillar degeneration, sarcosomal changes, dilatation of sarcoplasmic reticulum, formation of autophagic vacuoles, increase of lipofuscin granules and occurrence of vacuoles derived from endoplasmic reticulum and/or transverse tubules in some micrographs. Furthermore, edematous changes were developed at the same area where the degenerative changes were prominent. All of these cellular alterations could be related with ischemia resulting from local microvascular occlusion.