Studies on Myocardial Metabolism. III. Coronary Blood Flow, Myocardial Oxygen Consumption and Carbohydrate Metabolism in Experimental Hemorrhagic Shock12

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Abstract
Myocardial metabolism was studied in experimental hemorrhagic shock. Cardiac output, stroke volume and coronary blood flow were diminished during both oligemic and normovolemic phases of hemorrhagic shock. As a result of diminished coronary flow, the myocardial O2 usage was significantly reduced during both phases of shock. The myocardial O2 usage was depressed and cardiac efficiency declined during oligemia. Arterial concentrations of pyruvate and lactate were elevated during oligemic and normovolemic shock. The arterial glucose concentration which had risen during oligemia, declined during normovolemia. The myocardial extraction of lactate was increased in hemorrhagic shock. In contrast, elevation of arterial blood glucose concentration did not result in an increase in myocardial glucose extraction. In some instances, glucose concentration in coronary venous blood exceeded that in arterial blood. Myocardial pyruvate extraction was diminished, the pyruvate concentration in coronary vein blood frequently exceeded that in arterial blood. These data suggest that myocardial ischemia, resulting from a diminution in coronary flow, can bring about specific metabolic changes in the heart muscle, as for example, destruction of cocarboxylase.