Myocardial temperature management during aortic clamping for cardiac surgery. Protection, preoccupation, and perspective.

The temperature of the heart and the duration of aortic clamping are the two aspects of myocardial protection that receive the greatest amount of attention during many cardiac operations. Preoccupation with profound cardiac cooling has given rise to the development of multiple devices to keep the heart as cold as possible. This report is written to put into perspective the roles of hypothermia and aortic clamping in the overall strategy of myocardial protection. I also wish to (1) suggest that intraoperative myocardial damage is determined more by "how the heart is protected" than by "how long the aorta is clamped or how cold the heart is made," (2) question whether the benefits of deep cardiac hypothermia are sufficient to offset the monetary costs and morbidity that may result from its use, and (3) suggest that using all the measures currently available to prevent, avoid, and reverse ischemic and reperfusion damage is preferable to preoccupation with profound cardiac cooling.