中文摘要：

目的：探讨基于斑点追踪的二维应变成像技术评估小鼠急性心肌梗死后局部心肌功能不全的应用价值。方法：20只C57/B6小鼠随机分成两组：急性心肌梗死组（10只）和假手术组（10只）。所有小鼠均于术后3 d行超声心动图检查。应用EchoPac工作站分析左室乳头肌短轴切面高帧频图像,测量各节段收缩期峰值径向应变（peak radical strain,PRS）及应变率（peak radical strain rate,PRSR）,并用解剖M型超声测量左室舒张末期内径（LVIDd）及收缩末期内径（LVIDs）、左室舒张末容积（LVVd）、左室收缩末容积（LVVs）、射血分数（EF）和左室缩短率（FS）。结果：与假手术组相比,小鼠心肌梗死组LVIDd、LVIDs、LVVd、LVVs测值升高,EF、FS测值下降,差异有统计学意义（P〈0.01）;与假手术组相比,小鼠心肌梗死组各节段心肌PRS测值及PRSR测值均明显降低,差异有统计学意义（P〈0.01）;心肌梗死手术组前间隔、前壁、侧壁PRSR较其他节段心肌明显降低,差异有统计学意义（P〈0.05）。结论：二维超声应变成像技术可以准确量化评估小鼠急性心肌梗死后局部心肌功能不全。

英文摘要：

Objective：To investigate the value of two-dimensional speckle tracking imaging in assessing regional myocardial dysfunction in a mouse model of acute myocardial infarction. Methods： Twenty C57/B6 mice were randomly divided into two groups ： acute myocardial infarction （MI） group （n = 10） and sham-operation （SO） group （n = 10）. Echocardiography was performed three days after surgery. High frame rate two dimensional images were recorded in the left ventricular short axis views at the papillary muscle level and analysised at EchoPac workstation. Peak radical strain （PRS） and peak radical strain rate （PRSR） of each segment were measured at systolic period. Left ventricular internal diameter at diastole （LVIDd） and systole （LVIDs）, left ventricular volume at diastole （LVVd） and systole （LVVs）, ejection fraction （EF） and fractional shortening （FS） were measured with anatomical Mmodel echocardiography. Results： Compared with those of SO group, LVIDd, LVIDs, LVVd and LVVs of Mt group increased significantly（P 〈 0.01 ） while FS and EF reduced（P 〈 0.01） ; PRS and PRSR decreased significantly in all segments of MI group （P 〈 0.01）, compared with those of SO group; PRSR of anterosepetal, anterior and lateral segments in MI group decreased significantly than other segments（P 〈 0.05）. Conclusion：Two-dimensional strain imaging could accurately quantify regional myocardial function in a mouse model of acute myocardial infarction.