Extent of myocardial damage after open-heart surgery assessed from serial plasma enzyme levels in either of two periods (1975 and 1980).

Perioperative myocardial damage caused by cardiac surgery in 32 patients operated upon in 1980 is quantified in terms of total quantity of alpha-hydroxybutyrate dehydrogenase released from the heart into the circulation, and compared with perioperative myocardial damage in 32 patients operated upon in 1975. In the five year period between 1975 and 1980, various aspects concerning anaesthesia, pharmacological treatment, and myocardial preservation techniques have been subjected to considerable changes. Comparison of calculated myocardial damage in 1980 with that in 1975 shows a general reduction of about 40% in patients having coronary artery bypass grafting, 75% in patients with aortic valve replacement, and 10% in patients with mitral valve replacement.