The Myocardial Protective Effects Of L-carnitine In Patients Undergoing Open Cardiac Operation Under Cardiopulmonary Bypass

Objective To investigate the myocardial protective effects of L-carnitine in patients with congenital heart disease undergoing open cardiac operation under cardio-pulmonary bypass(CPB).Methods 40 patients with CHD randomly divided into two groups, test group (n=20)and control group(n=20). L-carnitine was put in the cold ST. Thomas II crystal cardiac arresting liquid in the test group(6g/L), other experimental conditions were the same between two groups. Before operation(T₁), 10 minutes after the aortic clamping (T₂)and at Oh (T₃), lh(T₄), 2h(T₅), 6h(T₆), 24h(T₇)after the aortic declamping, venous blood was drawn to test the level of serum creatine kinase (CK) and CK-MB isozyme. By the end of intracardiac procedure, a bit of myocardial tissue was taken to undergo electron microscopy, and the postoperative cardiac auto-rebeating rate were recorded.Results The level of CK, CK-MB in blood samples increased significantly in two groups after the aortic declamping, but the increasemagnitude in control group was more than test group( P<0.05);The postoperative auto-rebeating rate was $5% in the test group and significantly higher than that in the control group 70 % (P > 0.05). Electron microscopy showed only slight swelling of mitochondria in the cardial cell and the myocardial fiber was intact by the end of operation in the test group, however, in the control group swelling of mitochondria with vesicle formation, fissure of part of mitochondria ridges, and disappearance of glycogen particles were found.Conclusion As an ingredient of cardioplegia solution L-carnitine has a good protective effect on myocardium in patients undergoing open cardiac operation under CPB.