Effect of Interruption of Coronary Circulation on Metabolism of the Arrested Heart

Abstract

The experiments deal with the effect of complete myocardial anoxia on the oxygen usage and carbohydrate metabolism of the heart. Work was performed on heart muscle slices and on the whole heart in the closed chest dog. In experiments on the whole heart, arrest of the coronary circulation resulted in a gradual decline in myocardial oxygen usage after 2 hours. After 4 hours, the myocardial oxygen usage was negligible. Severe alterations in carbohydrate metabolism were observed, such as a significant increase in myocardial lactate production. In experiments on tissue slices, myocardial oxygen usage declined more rapidly. After 1 hour, only 40% of the initial Qo₂ remained. Aerobic glycolysis takes place in heart muscle slices as indicated by a significant increase in the RQ of this preparation.