The Protection Effects On Immature Myocardium Of Infants By Different Crystallized Cardioplegia

BackgroundThe cardiac surgical technique developed rapidly,especially in the young,minimally invasive,complex features,and it required us to maintain a long time without blood in the operation field,so inevitably it requires a good myocardial protection technique.After years of research,the theory of myocardial protection at adulthas had been established,but in children especially infants,because of the difference of immature myocardial structure and metabolism,the research on immature myocardium is less.Now the use of myocardial protection fluid(or cardioplegia)into the extracellular fluid type of cardioplegic solution in clinic is very common,but someone still use the fluid inside the cell type of cardioplegic solution.Therefore by way of studying clinical comparison,we can compare the effect of myocardial protection with Custodiol protective solution(HTK solution),which is represented by the intracellular fluid type crystal stop-beating solution,and the Modified ST.Thomas II as the representative of the extracellular fluid type crystal.OBJECTIVETo summarize the Protection effect of HTK Solution on Immature Myocardium in cardiac operation of infants.METHODS74 infants with congenital heart disease operated from January 2013 to October 2013,were divided into two groups: Modified St.Thomas Ⅱ solution group(group A)and HTK group(group B).The age at cardiac operation was below 3 months.The diagnosis included ventricular septal defect(VSD),atrial septal defect(ASD),tetralogy of Follot(TOF),double outlet right ventricle(DORV),complete atrioventficular septal defect(CAVC),etc.The moderate hypothermia was maintained during CPB.In the group A,myocardial perfusion during CPB was dependent on dose--20ml/kg,single time.In the group B,it was dependent on perfusion pressure--80 to 90 mmHg to make cardiac arrest and 30 to 40 mmHg to maintain,and the whole time was 5~7 minutes.The time to collect blood sample was after anesthesia,24 and 72 hours after operation.We measureed the serum level of cardiac troponin Ⅰ(cTnⅠ),creative kinase MB(CKMB),and lactate dehydrogenase(LDH).Clinical parameters including the auto-resucitation ratio,inotropic support requirement,mechanical ventilation duration,and the stay time in the intensive care unit were record.Ejection fraction(EF)was measured preperatively.Right atrial appendage cadiocytes’ mitochondria evaluated by Flameng’s method,were observed by electron microscope prior to the aorta clamped(Time 1)and before terminate the CPB(Time 2)RESULTSThe level of CKMB,LDH and cTnⅠin group B at the timing 24 hours after operation were lower than that in group A.In the clinical parameters,the EF showed that the myocardial damage in group B were less than that in group A.The structure of mitochondria maintained as originally.Loss of Matrix granule and swelling of mitochondria is found by chance.At Time 2,damage in mitochondria is found,such as loss of Matrix granule and cristae broken or Spongiform.The scores of evaluation by Flameng’s are increased in both groups(P<0.01).The scores of group A is higher than that of group B(P<0.05).CONCLUSIONThe protective effecte of HTK solution on immature myocardial in infants with congenital heart disease is obviously better than St.Thomas Ⅱsolution.