Improved myocardial protection with blood and crystalloid cardioplegia.

Although the results of coronary artery bypass surgery have been excellent, recent studies have demonstrated transient alterations in myocardial function and metabolism in spite of apparently adequate cardioplegic protection. Blood cardioplegia may provide better protection than crystalloid cardioplegia, but clinical studies remain inconclusive. Critical coronary stenoses limit cardioplegic delivery, and myocardial protection would be improved with either blood or crystalloid cardioplegia if the solution could be delivered beyond the coronary stenosis. The construction of proximal as well as distal anastomoses during a prolonged cross-clamp period permits more uniform cardioplegic delivery and immediate reperfusion when the cross clamp is released. This technique was used in a prospective randomized trial comparing blood and crystalloid cardioplegia. The long cross-clamp technique eliminated temperature gradients induced when cardioplegia was delivered into the aortic root. The technique of cardioplegic delivery may be as important as the solution used for cardioplegic protection.