Coronary endothelial damage after crystalloid cardioplegia.

There is considerable clinical experience to suggest that damage to the myocardium during ischaemic arrest can be prevented by cardioplegic solutions. However, very little is known about the effects of these cardioplegic solutions on the coronary endothelium. The effects of three different cardioplegic solutions on the coronary endothelium are reported here. Preservation of the myocardium was studied with biochemical assays. Blood cardioplegia did not damage the coronary endothelium. Crystalloid cardioplegia caused disappearance of the endothelial cells and gross deformity of the flow surface. The addition of albumin to the crystalloid solution preserved most of the endothelial lining. Preservation of the myocardial high energy compounds seemed to be dependent only on the cooling effect of the cardioplegia and not on the composition of the solution. There was no correlation between high energy compounds and endothelial changes. The present study favours the use of cold blood cardioplegia which preserves both the coronary endothelium and the myocardial energy sources during ischaemic cardiac arrest.