The Protective Effects Of HTK Cardioplegia On Immature And Hypoxia Myocardium In Cardiopulmonary Bypass

Objective : To evaluate the myocardial protective effects of Histidine-Tryptophan-Ketoglutarate (HTK) solution on immature and hypoxia myocardium in cardiac operation, through comparison with St.ThomasⅡcardioplegia (STH) and HTK cardioplegia in the operation of tetralogy of Fallot.Methods:Twenty infants with Tetralogy of Fallot who's weights less 10 kilogram were randomized into two groups. In group A (n=10) was perfused with HTK solution, and group B with STH solution. Evey infants was adjusted heart function actively before opration. After anesthesia, cardiopulmonary bypass was instituted, the ascending aorta was clamped. Then the cardioplegic solution was instilled. HTK solution (8~10℃) was instilled about forty milliliter per kilogram during six to eight minutes with 6/13 inch tube and one time was enough. STH solution (4℃) was instilled about twenty milliliter per kilogram the first time, after that it was done about ten milliliter per kilogram every thirty minutes until aortic crossclamp was removed. There was no significant difference between group A and group B in cardiopulmonary bypass (CPB) and operation. About 200mg right atrium tissue was cut, then put it in 4% Glutaral and cold preservation. The myocardial ultrastructuers were observed with electron microscope. The following clinical parameters were recorded, such as the aortic cross-clamping (ACC) time (min), the CPB time (min), the assist circulation time (min), the auto-beating time (s), the auto-beating rate (%), to sinus rhythm time (s), mechanical ventiating time (h), intensive care unit (ICU) time (h), the incidence of arrhythmia (%), the dose of inotropic drugs (Dopamine and Epinephrine). Get the blood sample before clamp the aorta. The serum levels of cardiac troponin I (cTnI), creatine kinase (CK) and creatine kinase MB (CK-MB) were measured at 3 minutes, 5 h, 22 h, 3 d, 6 d after referfusion. CK and CK-MB were measured at 3minutes, 5h, 22h, 3d after referfusion. Analysis of Statistics: statistically analysis all the data with SPSS 16.0. All the dates should be expressed with( x±S). Enumeration data will be analysis with Fisher probabilities. If p<0.05 means that the different of data has significant statistically.Results:1.Clinical parameters: Before ischemia, ACC time, CPB time, the assist circulation time were comparable no significant difference in two groups with (p>0.05). After ischemia, the auto-beating time, the auto-beating rate, to Sinus rhythm time, mechanical ventiating time, ICU time, the incidence of arrhythmia, the dose of inotropic drugs (Dopamine and Epinephrine) in group B were significantly lower than those in group A (P<0.05).2. The blood sample: The serum concentration of cTnI, CK and CK-MB were all no significantly before the ischemia in the HTK solution and STH solution (P>0.05).2.1 cTnI: After CCR 3 min, 5 h, 17 h, 3 d, the serum concentration of cTnI in group A was significantly lower than it in group B(p<0.05).2.2 CK and CK-MB: After CCR 3 min, 5 h, 22 h, the serum concentration of CK and CK-MB in group A were significantly lower than those in group B (p<0.05).3. Electron microscope show: the mitochondria in group A was better than that it in group B (p<0.05).Conclusions:Comparing with HTK solution and STH solution, HTK solution is benefit to the myocardial protection of immature and hypoxia myocardium in cardiopulmonary bypass and could provide satisfactory protection for the immature myocardium.