Normothermic Coronary Perfusion during Aortic Valve Replacement

Abstract Normothermic coronary perfusion was used in 121 patients undergoing aortic valve replacement from 1969 to 1976. Isolated aortic valve replacement was performed in 69% of the patients (84/121), and 31% (37/121) had combined procedures consisting of aortocoronary bypass, mitral valve replacement or repair, or ascending aortic aneurysm resection in conjunction with aortic valve replacement. The left ventricle was vented in all. Sinus rhythm was maintained in 105 patients, but spontaneous fibrillation persisted in 16. Postbypass hemodynamic data indicated satisfactory ventricular performance, and postoperative morbidity and mortality were low. Postoperative myocardial infarction (new Q waves, loss of R waves, persistent S-T and T wave changes) or a serum glutamic oxaloacetic transaminase (SGOT) level of more than 100 units (colorimetric) occurred in 13% of isolated and 27% of combined procedures. In patients with electrocardiographic and SGOT changes suggesting myocardial damage and in those with persistent spontaneous fibrillation, coronary perfusion was technically unsatisfactory owing to either excessive flow, low flow, inability to perfuse the right coronary artery, or high perfusion pressures. Evidence of myocardial damage was absent when coronary perfusion was appropriately applied. In order to obtain satisfactory results with normothermic coronary perfusion, both coronary arteries must be perfused at total flow rates of 200 to 350 ml per minute and at mean pressures of less than 120 mm Hg.