| The heart arrest and myocardial protection is always the focus problem during the open heart operation. Hypothermia and medium cardioplegia have been regarded as two elementary factors in myocardial protection and been used for a long time. However, with the rapid developments of basic study in ultrastructure of myocardium cell and and the technique of cardiac surgery, the shortages of cold crystalloid cardioplegic have been gradually recognized, especially for the immaturity myocardium who suffered from weak heart function, severe condition and cyanosis. Now days, cold crystalloid cardioplegic, cold or warm blood cardioplegic are still used in open heart operation in different degree. But the merits and shortages of them are apparent. Since there are differences in the structure of the myocardium, metabolism , and the tolerance to hypoxia between the adults and neonate, the methods of myocardial protection for the adult are not suitable for theneonate. It is the point to search for the best method of myocardial protection. According to " integrated myocardial protection" method put forward by Buckberg recently, We want to compare several methods by basic experimental research, evaluate the "integrated myocardial protection" method and probe the mechanism of myocardium impairment in order to offer the theoretical foundation and practical experiences for avoiding myocardial impairment. Moreover ,Amino acid , as a tricarboxylic acid cycle substate , has been proved to be able reduce impairment of reperfusion in infant myocardium protection. With the effects of amino acid being more recognized, we confirmed the protective effects of cardioplegia which is rich of amino acid simultaneously.MethodsWe established cyanosis model by reducing 02 supply for the immature Wistar male rats in order to imitate the anoxia patients in hospital. 40 anoxia immature Wistar male rats were devided into 5 groups randomly: 1. intermittent cold crystalloid cardioplegia; 2. intermittent cold blood cardioplegia; 3. Warm blood induction with intermittent cold blood cardioplegia and then followed by hot shot; 4. like the group 3, but with the terminal warm substrate - enriched blood cardioplegia reperfusate; 5. control group. We compared the differences between groups and examined hemodynamics result, energy metabolism myocardial enzymology, the degree of reperfusion impairment, myocardium ultrastructure, and the expression of early gene of reperfusion impairment: c-fos and c-jun, in order to approve the advantages and mechanism of integrated myocardial protection.ResultsDuring the experiment, the modified model can imitate cyanosis congenital heart disease steady, which ensure the success of experiment. After experiment, most of the heart, except one case in CC group, came back to work without artificial assistant. The result of resuscitation in WB and WBA groups better(P <0. 01). It takes few time to come to work, and the heart beat strong and in similar rhythm. The heart in CC group decline in heart rhythm , heart rate , heart function comparing with the other groups. In energy metabolism of myocardium WB and WBA group are nearly normal after resuscitation . CB group is next to them . The energy consume in CC group is the low-est(P <0. 01). CB group is better, and there are no differences a-mong the other groups( P > 0.05 ). The results of myocardium reperfu-sion impairment indicates that the impairment in CC group is most severe, and the WBA group is gentlest . The difference between groups is apparent( P <0. 01). The results of myocardium ultrastructure and the express of answering gene in early state of inflammation also support the upper results , which indicates that the myocardium protection effect in CC group is inferior to the other. Though the myocardium protection effects in CB group is superior to CC group in some degree ( P <0.01) ,they are inferior to WB and WBA group. The anterior offer similar protective effects , but they can not catch up with the later in energy preserve and ultrastructure . WBA group c...
|
PDF Full Text Request