Metabolism and Function of the Heart During Acute Asphyxia and in Postasphyxial Recovery

In asphyxia, the energy production by anaerobic glycolysis does not suffice to meet the energy demand of the heart. This energy deficit results in a rapid and complete depletion of creatine phosphate, and in a continuous decrease in ATP and the sum of adenine nucleotides. Upon restoration of the oxygen supply, the creatine phosphate returns to normal within 1-2 minutes. Restoration of ATP and the sum of adenine nucleotides may require many hours and is determined by the depletion of the degradation products of the nucleotides which takes place during the anaerobic period. In the anaesthetised rabbits subjected to asphyxia myocardial power is rapidly and profoundly depressed, but returns to normal within 1-2 minutes if artificial ventilation is applied, and asphyxia has not exceeded 5 minutes. The impaired cardiac performance during asphyxia and its postasphyxial restoration changes with the myocardial creatine phosphate and a small portion of the cellular ATP which is thought to be associated with the contraction process.