title: Ultrastructural changes of the dog myocardium in extracorporeal circulation.
abstract: The effects of the cardiopulmonary bypass circulation on the cardiac muscle cells were studied electron microscopically. Subendocardial hemorrhage was commonly recognized in both ventricles. However, it appeared earlier and more severely in the right ventricle than in the left ventricle. Clear flocculent areas containing numerous filamentous structures were originated from degradation of myofibrils. Degradation of myofibrils occurred within 1 hour after bypass circulation. Degenerative changes of myocardial cells such as zonal lesions, contraction bands and swelling or condensation of mitochondria appeared in both ventricles. Damages of myocardial cells in right ventricular wall were more severer as compared with those in the left throughout the period of observation.
mesh_terms: D000818:Animals; D004285:Dogs; D005112:Extracorporeal Circulation; D008929:Mitochondria, Heart / Q000648:ultrastructure; D009206:Myocardium / Q000648:ultrastructure*