Abstract
Fifty patients undergoing mitral valve replacement were studied during operation by measuring the duration of extra-corporeal circulation and, after operation, by hemodynamic measurements and determinations of myocardial enzymes (total CK, CK-MB, GOT) . Myocardial protection was accomplished by topical cardiac cooling only in 10 patients (group I), crystalloid glucose-potassium cardioplegia with topical cardiac cooling in 20 patients (group II), and oxygenated crystalloid cardioplegia (St. Thomas solution) with topical cardiac cooling in 20 patients (group III) . Total extra-corporal circulation time and aortic clossclamp time were the longest in group III, and the difference between group I and group III were seen (p<0.01) . As the enzymic activity increased postoperatively in all groups, there were no significant difference in each groups. Cardiac Index were maintained over 2.01/min/M2 in all groups during postoperative period in ICU, however, high left atrial pressure and multidose administration of catecholamine were needed in group I to keep the constant cardiac output, on the other hands, good cardiac output were maintained in group III at low left atrial pressure. Early postoperative cardiac function was the best in group III and the worse in group I. As cardioplegia showed good myocardial protective effects, oxygenated crystalloid cardio-plegia reduced ischemic myocardial injury and permitted better functional recovery. Oxygen-ated crystalloid cardioplegia provides superior protection for mitral valve replacement.
