Clinical observations and gross and microscopic morphology of the hearts of 50 patients who died at various intervals following aortocoronary saphenous vein bypass procedures are presented. Time of total cardiopulmonary bypass varied inversely with survival time among these patients. Myocardial necrosis with contraction bands and/or hemorrhagic myocardial necrosis was observed in the hearts of 44 of the 50 patients. Pathogenesis of the acute myocardial necrosis with contraction bands was multifactorial: anoxic arrest, cardiotonic drugs, electrical defibrillation, electrolyte imbalance, microthrombi, and hypoperfusion are incriminated. Subendocardial hemorrhagic necrosis was present in 17 of 40 patients whose postoperative survivals were 4 days or less. Its frequency increased with duration of survival. Hypoperfusion of the myocardium is suggested as the major etiologic factor of the subendocardial hemorrhagic necrosis. Myocardial lesions observed among these 50 patients did not differ from those in patients who had open heart surgery for other reasons.
ASJC Scopus subject areas
- Pathology and Forensic Medicine