Depressed cardiac performance after mitral valve replacement. A problem of myocardial preservation during operation.

Our experimental studies since 1972 show that the heart is preserved best during cardiopulmonary bypass when it is in the beating, nonworking state. Results after mitral valve replacement (MVR) from 1968 to 1974 using various techniques of cardiac preservation were compared. In group I were 47 patients (1968 to 1972) in which either profound, topical hypothermia with prolonged ischemic arrest (19) or ventricular fibrillation with continuous coronary perfusion (28) was used. In group II there were 22 patients (1972 to 1974) in whom the heart was in a beating, nonworking state between brief periods of ischemic arrest. In group I 55% (25/47) required inotropic support postoperatively, and 17% (8/47) died. In group II 5% (1/22) required inotropic support postoperatively, and this patient died (5% mortality). Extended periods of ischemic arrest were necessary because of intraoperative complications in this patient. These data show that depressed postoperative myocardial performance occurs rarely when the heart is preserved in the beating, nonworking state during MVR and ventricular fibrillation and prolonged topical hypothermic anoxic arrest are avoided.