[Anoxic myocardial lesions in man, developed during extracorporeal circulation, studied by electron microscopy].

Anoxemic changes of the myocardium were examined at 20 patients operated on in extracorporal circulation. At a mild degree hypothermia (30 degrees C) morphological changes appear after a 20 minutes period of anoxaemia. Damage to the myocard of irreversible character could be revealed after an anoxaemic period of 43--55 minutes. An intermitting perfusion of the coronary arteries delayes the formation of the lesions, although in cases of ligation of the aorta for 90 minutes severe mitochondrial changes and deformation of cells were seen. The best method for protecting the myocard is an isotherm perfusion of the coronary arteries. Clinical and laboratory findings show that necrosis of the myocard has a focal character and may play a part in formation of postoperative lesions.