Chest, Vol 80, 80-84, Copyright © 1981 by American College of Chest Physicians

ARTICLES

Effects of cardiopulmonary bypass on the dynamics and coronary circulation of the normal heart

P Magrassi, L Dumont, P Stanley and C Chartrand

This study observed the consequences of total normothermic cardiopulmonary bypass (CPB) on cardiac function, myocardial blood flow, and its regional distribution. To determine the potential effects of CPB per se on hemodynamic performance of the heart from the concomitant interfering influences of anesthesia, surgical procedure, and preexisting disease, myocardial function and blood flow were investigated in two groups of normal animals submitted to identical experimental conditions, except for two hours of total CPB, which was performed in only one group. Myocardial blood flow distribution was studied immediately before and after CPB, and the hemodynamic studies were performed 3, 24, and 48 hours postoperatively in the awake resting animal. Coronary blood flow and its distribution were similar before and after CPB. Three hours postoperatively, the hemodynamic status of the perfused dogs seemed to be slightly inferior compared with control subjects; however, there was no statistically significant difference between the two groups. Twenty-four and 48 hours after surgery, the cardiovascular dynamics were similar in both groups. These results demonstrate that two hours of total normothermic cardiopulmonary bypass have no significant deleterious effect on the performance, coronary perfusion, and its regional distribution, of the normal beating empty heart.