Experimental studies on myocardial metabolism of carbohydrate and lipid in surface-induced deep hypothermia

In surface-induced deep hypothermia, metabolic acidosis resulting from lactacidemia was observed. In the aspect of myocardial metabolism, the rate of reduction in coronary A-V difference ratio of lactate, pyruvate and NEFA was less than that of coronary flow and myocardial oxygen consumption in the hypothermic heart. Namely, it seems that lactate, pyruvate and NEFA play an important role as energy fuel in the hypothermic heart. On the other hand, myocardial metabolism of glucose was reduced in the hypothermic heart. Moreover, it seems that exogenous corticosteroid and ATP do not influence on the myocardial metabolism of carbohydrate and lipid in the hypothermic heart.