Role of Hypothermia in the Protection of Myocardial Metabolism during Cardiopulmonary By-Pass and Elective Cardiac Arrest

¹ The Departments of Surgery and Biochemistry, Medical College of Georgia.

Appraisal of the biochemical effects of hypoxia upon myocardium during cardiopulmonary by-pass and hypoxic arrest with and without hypothermia has been presented. Metabolic processes were less altered after one hour of hypoxic arrest when hypothermia was used than after 30 minutes at normothermia. Progressive decrease in this protection occurred with passage of time, but some degree of protection was demonstrated after a four and one half hour period of arrest. The correlation between these biochemical findings and observations of myocardial function has been presented. It is suggested that less impairment in myocardial function after hypoxic arrest may result from maintaining a normal body temperature with selective myocardial hypotherimia.