Clinical Study Of Hypothermic Ventricular Fibrillation On Cardiopulmonary Bypass For Open-heart Surgery

Objective: To access the effect on myocardial protection of using hypothermic ventricular fibrillation technique for open-heart surgery.Methods: there were patients with congenital heart disease ventricular septal defect(n=20) and acquired cardiac valvular disease mitral stenosis (n=20) who endured the cardiac surgery procedures the first time . The patients were randomly divided into two groups respectively . The patients in control group experienced cold crystalloid cardioplegia (CC,n=20) and in experimental group , hypothermic ventricular fibrillation with no aortic cross-clamping (HF,n=20). Cardiac troponin I (cTnl), Creatine kinase MB (CK-MB),superoide dismutase (SOD) and malonyldialdehyde (MDA) were measured . Serial venous blood samples were collected from 40 patients before cardiopulmonary bypass(CPB), 2hrs, 6hrs, 12hrs, 24hrs, and 48hrs after resumption of heart beating. The myocardial tissues were taken from right atrium for observing the myocardial ultrastructure changes.Results: All serum enzymes increased both groups HF and CC postoperatively. The serum lever of cTnI, CK-MB and MDA were significantly lower in group HF than in group CC(p<0.05), especially the lever of cTnI(p<0.01), the lever of SOD was higher in group HF than in group CC postoperatively (P<0.05). The myocardial ultrastructure damaged postoperatively In group CC and there were no significant changing before and after the process of CPB in group HF.Conclusion: Since there was no aortic clamping and perfusion cardioplegia, the supply for myocardium with continual blood and oxygen, no ischemic-reperfusion mjury.The hypothermic ventricular fibrillation technique reduce the myocardial injury. So it is a safe way on myocardial protection for open-heart surgery.