Study On Myocardial Protection For Off-pump Coronary Artery Bypass Grafting Of Levocarnitine Postprocessing And Ischemic Postprocessing

Objective:Ischemic postcondition(IPO)is a repeated transient perfusion before ischemic reperfusion of tissue,which has been proved to have a protective effect on myocardial ischemia reperfusion injury.Drug postcondition has also been extensively studied,L-carnitine plays a crucial role in lipid metabolism.The main source of energy required for myocardial cell motility is the oxidative metabolism of lipids,so,L-carnitine has obvious protective effect on hypoxic ischemic tissue.At present,there is less research on the ischemic treatment after coronary artery bypass grafting.In this study,L-carnitine postprocessing was compared with traditional surgical methods of postprocessing on ischemic myocardial protective effect in off-pump coronary artery bypass grafting surgery,which will provide evidence for cardiac protection in clinical cardiac surgery.Method:From January 2016 to January 2017,180 patients with coronary artery bypass grafting in our hospital were selected,and randomly divided into levocarnitine postprocessing(A,n=62)and Ischemic postcondition group(B,n=57)and control group(C,n=61),inclusion criteria: patients met criteria for the diagnosis of coronary heart disease WHO according to the coronary angiography shows vascular stenosis,70%,surgical indications clearly,elective CABG,all operations were performed by the same surgeon.Exclusion criteria: 1)serious lung,liver and kidney dysfunction,2)emergency surgery,3)myocardial infarction in January 4),LVEF < 40%,5)than CABG.Intramuscular injection of scopolamine 0.3mg/kg in patients before surgery,followed by intravenous injection of midazolam,fentanyl,etomidate,vecuronium,then,rapid intravenous induction and tracheal intubation,and maintain the PetCO2 within the normal range.Injection Fentainilai maintain anesthesia when rewarming before surgery and before CBP,When necessary,patients inhale isoflurane.Left radial artery was punctured and catheterized after tracheal intubation.All patients were treated with extracorporeal circulation,left internal mammary artery was anastomosed to anterior descending branch,and the great saphenous vein was anastomosis to other coronary artery.In the operation process,levocarnitine 20mg/kg was dissolved in 20 ml saline and injected slowly before cardiac arrest in A group.After anastomosis of left internal mammary artery and anterior descending,the internal mammary artery was clipped three times with the forceps,each 30 s,interval 30 s.Then open up the aorta.The control group was treated with coronary artery bypass grafting without medication and physical treatment.Serum cardiac troponin I(cTn I),creatine kinase(CK),creatine kinase MB isoenzyme(CK-MB)were detected after 0h,8h,24 h of CABG by automatic biochemical analyzer.The cardiac index(CI)and left ventricular ejection fraction(LVEF)were evaluated in preoperative 1D and postoperative 4D.Automatic heart rate and the dosage of vasoactive drugs were recorded.Result:There was no significant difference in serum CK,CK-MB and cTnI levels among the three groups before operation(P?0.05),while,the levels of CK,CK-MB and cTnI in serum of three groups were significantly increased after the ascending aorta was opened and reached the highest value within 24 hours.The CK-MB values of A group and B group at 8 hours(P =0.000)and 24 hours(P =0.000)were significantly lower than those in the control group.There was no significant difference in CI and LVEF on the day before surgery,but on the fourth day after operation,CI and LVEF in A group(P =0.000)and B group(P =0.000)were significantly better than those in control group.The use of carnitine in cardiopulmonary bypass coronary artery bypass graft has strong protective effect on myocardial cells.The protective effect on myocardial of L-carnitine and traditional ischemic postprocessing was similar.L-carnitine is low price and can be obtained conveniently,intraoperative administered by anesthesiologists.It can shorten the operation time,and is worth popularizing in clinical cardiac surgery.Vasoactive drugs in the control group was significantly higher than that in the A group and the B group.Conclusion : L-carnitine in cardiopulmonary bypass coronary artery bypass graft has strong protective effect on myocardial cells.The protective effect on myocardial of L-carnitine and traditional ischemic postprocessing was similar.L-carnitine is low price and can be obtained conveniently,intraoperative administered by anesthesiologists.It can shorten the operation time,and is worth popularizing in clinical cardiac surgery.