The Myocardium Protective Effect Of Ischemic Post-conditioning Technique And Meglumine Adenosine Cyclophosphate Pre-conditioning In CABG

CK-MB is the creatine kinase(CK) isoenzymes, mainly in the myocardium in cardiac operation, after CK-MB in the blood will increase. CTn I is a kind of myocardial contractile regulatory proteins, in cardiac surgery will be higher, but its sensitivity and specificity was significantly higher than that of creatine kinase(CK). Creatine kinase isoenzyme(CK-MB). CTNI, CK-MB will be used as evaluation index of myocardial injury. in the cell.Cyclic adenosine monophosphate(c AMP) is the important materials that involved in the biological functions,which is an important second messenger.It can improve the ability of antiinjury of myocardium cell. Meglumine adenosine cyclophosphate is one of the most importantderivatives of c AMP, Meglumine adenosine cyclophosphate were decomposed into adenosine and phosphate,which transshipped into the myocardial cell firstly through the effects of meglumine., at the same time meglumine inhibit the biological decomposition of the enzyme on c AMP,.so adenosine and the inhibition will enhance the myocardial protective effects.This is the mechanism.29 years ago, Murry et al. first confirmed that brief ischemia and reperfusion may reduce myocardial infarct size before sustained ischemia, and it was named “ischemic preconditioning”.12 years ago, Zhao et al. demonstrated that 3 times brief I/R treatment will reduce the area of myocardial infarction on canine myocardial, and the myocardial protective effect was designated “ischemic postconditioning”:After sustained ischemia,but before reperfusion,many times brief I/R treatment may alleviate myocardial reperfusion injury by activating endogenous protective mechanism.Objectinve: Coronary artery bypass grafting(CABG) with cardioplegic arrest is associated with myocardial injury.The aim of this study was to investigate whether three methods that are a mechanical ischemic post-conditioning(IPO) technique 、 Meglumine adenosine cyclophosphate pre-conditioning(MAC)and the combined use of the pre-conditioning and the post-conditioning(IPO+MAC) have a myocardial protective effect by enhancing recovery of the heart following revascularization.Methods:One hundred fifty-four adult patients undergoing coronary artery bypass grafting were randomized to IPO group(n=39) 、 MAC group(n=41)、IPO+MAC group(n=35)or control group(n=39).We measured the CK-MB,c TNI of myocardial enzymes instantly by collecting venous blood before CABG and the time of 30 minutes、6 h、24h、48h、72 h after CABG.The left internal thoracic artery was used in all cases to bypass the LAD(the left anterior descending artery) 。 In IPO group or IPO+MAC group:After bypass anastomosis having been completed, ischemic Postconditioning was performed by three cycles of 30 s ischemia and 30 s reperfusion using bulldog to clamp the left internal thoracic artery。In MAC group or IPO+MAC group, MAC(0.5 mg/kg) was infused via central vein after induction of anesthesia,which the speed is 0.02mg/kg/min. In control group or IPO group,same volume normal saline was infused instead of MAC.Date were showed as mean ± standard deviation(x±s),and analyzed with Independent-Samples T Test and Chi-square tests by using SPSS 13 statistical software, It was identified statistically significant that P is less than 0.05.Results: 1 CK-MB 1.1 The MAC group compared with control group, there was statistical significance in 24 h、 48 h after CABG. There was no statistical significance in 30 minutes、6 h、72 h after CABG. IPO group, MAC + IPO group compared with control group respectively, there was statistical significance in 6 h, 24 h after CABG. There was no statistical significance in 30 minutes、48 h、72 h after CABG. 2.1 MAC group compared with MAC + IPO group, IPO group compared with MAC + IPO group, there was statistical significance in 6 h after CABG. 2 c TNI 2.1 MAC group 、 MAC + IPO group compared with control group respectively, there was statistical significance in 6h、24 h、 48 h、72h after CABG; IPO group compared with control group, there was statistical significance in 24 h、48 h、72h after CABG. 2.2. MAC group compared with MAC + IPO group, there was statistical significance in 6h、24 h、48 h after CABG. IPO group compared with MAC + IPO group, there was statistical significance in 6h、24 h、48 h after CABG.Conclusion: Simple meglumine adenosine cyclophosphate preconditioning and simple ischemic postconditioning can relieve myocardial injury, but the combination of the two methods will get better myocardial protection effect.