中文摘要：

目的采用超声斑点追踪成像（STI）多层分析技术评价兔心肌药物后适应的局部纵向心功能变化。方法40只兔随机分为2组：单纯缺血再灌注组（IR组）与药物后适应再灌注组（ATP—PPost组），两组分别于冠状动脉阻断前、阻断后45min，再灌注30min、60min及120min进行图像采集。每组于冠状动脉阻断后45rain、再灌注30min、再灌注60min后分别随机抽取2只兔及剩余兔于实验结束后行病理学检查。结果①冠状动脉阻断45min后，两组模型兔左室射血分数（LVEF）减低（P〈0．05），左室局部心内膜应变（SLsys—endo）、心肌应变（SLsys—mid）、心外膜应变（SI。sys—epi）绝对值均明显降低（P〈O．01），且心内膜变化幅度高于心外膜（P〈0．01）。②与阻断后比较，ATP—PPost组再灌注30min后左室SLsys—enclo、SLsys—mid，SLsys—epi绝对值均增高（P〈0．01），且随再灌注时间延长SLsys—endo绝对值继续增高（P〈0．05）；组间比较，ATP—PPost组再灌注各时间点SLsys—endo、SLsys—mid、SI．sys—epi绝对值均较IR组增高（P〈0．01）。③两组各状态下SLsys—endo、SLsys—mid、SLsys—epi绝对值均呈递减状态，各时间点SLsys—endo绝对值均高于SLsys—epi（P〈O．01，0．05）。结论STI多层分析技术可准确评价兔心肌药物后适应模型左室局部纵向心肌功能变化特征，心内膜应变较心外膜更加敏感。

英文摘要：

Objective To evaluate the effect of pharmacological postconditioning on longitudinal myocardial function in rabbits＇ model of myocardial insbemia-reperfusion using layer-specific strain of ultrasound speckle tracking imaging. Methods Forty healthy rabbits were randomly divided into two groups： ischemia-reperfusion group （IR） and pharmacological postconditioning group （ATP-PPost）. Echocardiography examinations were performed at baseline, 45 min after ligation and 30 rain, 60 rain, 120 min after reperfusion. Pathological examinations were applied in two rabbits randomly selected from each group at 45 rain after ligation and 30 min,60 min after reperfusion and at the end of experiment. Results （DAfter coronary artery ligation, left ventricular ejection fraction （LVEF） decreased in two groups （ P 〈0.05） and longitudinal systolic strain（SLsys） of 3 myocardial layers decreased in two groups （ P〈0.01）. And the SLsys in the endocardium had greater variation than that in the epicardium. Compared with that after ligation, the SLsys of all myocardial layers increased at 30 rain after reperfusion in ATP-PPost group （P〈0.01）, and the SLsys in endocardial layer kept increasing with the time of reperfusion（ P 〈0.05）. And the SLsys of 3 myocardial layers were significantly higher in ATP PPost group than those in IR group （P 〈0.01）. In two groups, the values of SLsys were decreasing from endocardial layer to epicardial layer. They were higher in the endocardium than those in the epicardium at any time（ P 〈0.01 and P 〈0.05）. Conclusions Layer-specific strain of STI can evaluate exactly the regional myocardial function of rabbit myocardial pharmacological-postconditioning model. SLsys of endocardial layer is more sensitive tomyocardial ischemia than that of epicardial layer.