摘要：目的 通过与三种经典心肌保护方法比较，探讨含血利多卡因高钾(血利钾)心停搏液和双向灌注心肌保护法的心肌保护作用。方法犬20只，随机分成四组(n=5)，分别用晶体心停搏液(CG1)、冷稀释血心停搏液(CG2)、常温稀释血心停搏液(CG3)及血利钾心停搏液(EG)。每组均经历120min心脏缺血。观察心脏停搏情况、冠状静脉窦回流血量及心肌酶浓度、心肌细胞内钙离子(Ca2+)和丙二醛(MDA)及三磷酸腺苷(ATP)含量、心肌形态学改变。结果 ①实验组(EG)心脏停搏时间短，心停搏液用量少，冠状静脉血流量及心肌氧摄取率在缺血前后无明显变化；②血清心肌酶水平各组间无显著差异；③EG再灌注心肌Ca2+超负荷及ATP含量下降较CG3明显，与CG2相似；④EG再灌注心肌MDA水平较CG1显著降低。⑤心肌形态学改变各组间无显著差异。结论 血利钾心停搏液和双向灌注具有确切的心肌保护作用。

    关键词：缺血-再灌注损伤；心停搏液；心肌保护；体外循环

    Cardioprotective Effects of Lidocaine-Hyperpotassium-Blood Cardioplegic Solution with Combined Delivery Routes on Ischemia-Reperfusion Injury in Canine Hearts

    ZHANG Xiao-hua, ZHANG Jing-fang, WU Ruo-bin, XIAO Xue-jun, CHEN Ping

    (Department of Cardiac Surgery, Guangdong Cardiovascular Disease Institute,Guangzhou 510080, China)

    Abstract: OBJECTIVE To investigate the myocardial protective effects of lidocaine-hyperpotassium-blood cardioplegic solution with combined delivery routes by comparing to three most widely used strategies of myocardial protection.METHODS 20 adult canines were placed on cardiopulmonary bypass (CPB) and randomized to receive four myocardial protective protocols respectively (5 in each group): cold supplementing St. Thomas Hospital crystalloid solution cardioplegia antegradely and intermittently (CG1), hypothermic blood cardioplegia antegradely and intermittently (CG2), warm blood cardioplegia antegradely and continuously (CG3), and lidocaine-hyperpotassium-blood cardioplegia with combined routes(EG). Each group underwent CPB and was submitted to 120 minutes of myocardial ischemia and a 30 minutes period of reperfusion. Arrest of the heart and coronary venous sinus flowrate were recorded. Serum cardiac enzymes and myocardial intracellular malondiadehyde (MDA), ion calcium (Ca2+), adenosine triphosphate (ATP) were measured. Myocardial structure changes after ischemia and reperfusion were observed with optical and electronic microscope.RESULTS Lidocaine-hyperpotassium-blood cardioplegic solution with combined delivery routes shortened the time of arrest of the heart, and decreased the volume of cystalloid cardioplegic solution used. There was no significant difference in coronary sinus blood flowrate (CSF) and myocardial retrieval oxygen (MRO) between post- and pre- ischemia in all groups. There was no significant difference in increase of serum cardiac enzymes after ischemia comparing EG with control groups. Myocardial intracellular Ca2+ overload and exhaustion of ATP during reperfusion in EG were obvious comparing to CG3, and similar to CG2. The level of myocardial intracelluar MDA after 30 minutes reperfusion in EG was significantly lower comparing to CG1. No significant difference in structural changes were detected between the groups. CONCLUSION Comparing with other classical techniques, cardioplegia with lidocaine-hyperpotassium-blood cardioplegicsolution and combined delivery routes represents a simple, safe and effective method of myocardial protection which may be an alternative to traditional cardioprotective techniques. ......