Comparison of continuous versus intermittent warm blood cardioplegia during coronary artery bypass grafting / 中华麻醉学杂志

ABSTRACT

Objective To examine the difference in myocardial protection provided by continuous and intermittent warm blood cardioplegia during coronary artery bypass (CAB) .Methods Thirty ASA Ⅰ-Ⅱ patients undergoing CAB with warm CPB were randomly divided into two groups : (A) continuous warm blood cardioplegia ( n = 15) and (B) intermittent warm blood cardioplegia ( n = 15) . During CPB the body temperature was maintained at 33℃ -34℃ . Arterial blood samples were taken before skin incision (T0) , 1 h after going on CPB (T1 ) and 6h , 24h after coming off CPB (T2, T3 ), for determination of plasma concentration of cardiac troponin T (cTnT) using ELISA method. A small piece of myocardium was obtained from right ventricle (about 1g ) before aortic crass-clamping and after the aortic clamp was removed for determination of myocardial ATP content and ultrastractural examination. Results The demographic data were comparable between the two groups. Plasma cTnT level increased significantly at T1 and T2 as compared with the baseline values (T0) and then returned to normal level at T3 in both groups. The cTnT level was significantly higher in group B than that in group A at T2 (6h after weaning from CPB)The myocardial ATP content decreased significantly after aortic clamp was removed as compared with that before cross-clamping of aorta, but myocardial ATP content in group A was significantly higher than that in group B after release of arotic clamp. Mitochondria score was significantly higher after release of aortic cross-clamp than that before aortic cross-clamping.Conclusion Continuous warm blood cardiaplegia is superior to intermittent warm blood cardioplegia during CPB in terms of myocardial protection.