Hemodynamic Evaluation of Continuous Normothermic Aerobic Blood Cardioplegia

Continuous normothermic blood cardioplegia is a new technic of myocardial preservation during cardiac operations. This is stated to permit for aerobic arrest and to overcome many of the disadvantages of ischemic hypothermia including detrimental effects on enzymatic functions and cellular integrity. In the period between September 1991 and November 1991, 10 patients who underwent coronary artery bypass grafting were operated with this technic. Nine of them were male, 1 was female and their ages ranged from 34 to 69 (mean 53± 10). At the operation 2 to 4 distal anastomoses were performed (2.7±0.8 distal anastomoses per patient). The heart was maintained chemically arrested at 37° C throughout the operative procedure. Blood cardioplegia was administered at 37° C via a system which mixes and warms a hyperkalemic crystalloid solution with oxygenated blood in a 1:4 dilution. After the initial infusion of 1500 ml of high-potassium warm-blood cardioplegia, the low-potassium diluted blood was continuously perfused. All of the patients were converted to normal sinus rhythm spontaneously after removal of the aortic crossclamp. There was no perioperative myocardial infarction, no need for inotropic support or IABP. Cardiac index 24 hours after bypass was significantly higher (2.61±0.49 versus 3.40±0.61 lt/mn/m2, p<0.02) than before bypass and there was no morbidity or mortality. We can thus confirm that this is a safe alternative method for myocardial protection.