The Comparison Of Myocardial Protection By Lower Limb Remote Ischemic Preconditioning And Heart Ischemic Postconditioning In Children Heart Surgery

Objective: Classic ischemic perconditioning (IPC) reduces the myocardial ischemia-reperfusion(I/R) injury. The remote ischemic preconditioning (RIPC) and ischemic postconditioning(IPO) had been also proved their similar effect in preventing the myocardium from I/R injury in a large amount of animal experiments and a few clinical trials. No reports pertaining to a comparison of myocardial protection by remote lschemic preconditioning and heart ischemic postconditioning in cardiac surgery have been found up to now. In this study, lower limb ischemic preconditioning and cardiac of ischemic postconditioning were conducted respectively in children with congenital heart disease underwent repair of ventricular septal defect and the protective effects of RIPC and IPO were compared on myocardium I/R injury in paediatric cardiac surgery.Methods: Sixty patients were selected in our department underwent a repair of ventricular septal defect from April 2008 to January 2009. The age ranged of patient ranged 1-5 years old, and they were divided randomly into three groups: RIPC group(n=20), IPO group(n=20)and control group(n=20). Patients' guardian signed a consent form before surgery. The cuff in the right thigh was used in RIPC group after anesthesia intubation nasal, inflatable cuff and the pressure was maintained at 200mmHg for 5min. Then deflate the balloon for 5min. The cycle was repeated for 3 times. The IPO group started after aortic de-clamping for 30 seconds. Then, aortic was re-clamped for 30 seconds again resulting in heart ischemia. After that, the aortic clamp was released for 30 seconds in order to achieve complete myocardial reperfusion. This cycle was repeated 3 times. The control group was not proconditioned or postconditioned. The bypass time, aortic cross-clamping time, the proportion of spontaneous fibrillation, postoperative mechanical ventilation time and intensive care unit (ICU) length of stay and other clinical data were recorded in three groups. The CK-MB and cTnI was measured before surgery, six and twenty hours after aortic de-clamping.Results: Three groups of patients in age, weight, cardiopulmonary bypass time, aortic cross-clamp time and preoperative CK-MB and cTnI were not significantly different(P> 0.05). The CK-MB and cTnI of three groups were increased significantly than the basis of value in 6 hours and 20 hours after aortic de-clamping. 6 hours after aortic de-clamping ,the CK-MB in RIPC group IPO group were significantly lower than in control group(p=0.000);20 hours after open aortic, the CK-MB in three groups was not significantly different (p=0.403); 6 and 20 hours after aortic de-clamping, the cTnI in RIPC group and IPO group were lower than control group ( p=0.002 and p=0.020). The CK-MB of RIPC group and IPO group were not significantly different at three timepoints (p> 0.05).The cTnI of RIPC group and IPO group were not significantly different at three timepoints (p > 0.05).Conclusion: The present study suggested that both RIPC and IPO can reduce the myocardial ischemia-reperfusion injury in children heart surgery; The RIPC and IPO provide the same protective effect with respect to reduce postoperative CK-MB and cTnI release.