Cardiac sequelae of haemorrhagic shock

Using selective cardiac catheterization and a 133Xe wash-out technique, myocardial blood-flow and oxygen utilization were studied in greyhounds during and following brief and prolonged haemorrhagic hypotension. The progressive fall in myocardial oxygen extraction as the shock period was prolonged and the subsequent failure of myocardial oxygen consumption to rise during re-infusion suggested the presence of a metabolic defect in the myocardial cell. The use of a special ‘elemental’ diet was shown to eliminate the intestinal blood-loss typical of canine haemorrhagic shock models; despite this the apparent myocardial cellular metabolic defect persisted. In addition, a myocardial depressant factor which depressed myocardial function in vitro was isolated from ultrafiltrates of post-shock plasma.