ABSTRACT
The authors studied the changes of myocardial enzymes (CPK, CPK-MB, LDH) in the wall of the right atrium during cardioplegic arrest in ninsecutive patients who had an open heart operation, observed the changes of these enzymes in seium as well The results indicate that when the crystalloid cardioplegic solution, systemic moderate hypothermia and decp local hypothermia are used to protect the myocardium, the right atrium can get satisfactory protection during cardioplegic arrest and there is no statistical differences of enzyme changes between samples taken from the right atrium before and after the arrest. The article still discussed the possibility of using the changes of atrial myocardial enzymes as an index to reflect the extent of myocardial protion. The authors consider that the change of myocardial enzyme can better reflect the metabolic activity of myocardium during cardioplegic arrest.