BACKGROUND Persistence of subtle abnormal myocardial deformation such as postsystolic shortening (PSS) after transient ischemia can be used to diagnose a history of myocardial ischemia (myocardial ischemic memory). Furthermore, early systolic lengthening (ESL) has recently attracted attention as another marker of myocardial ischemia. However, it is unclear whether the persistence of such abnormal deformation can be detected by three-dimensional (3D) speckle-tracking echocardiography, which has relatively low spatial and temporal resolution compared with two-dimensional echocardiography. The aim of this study was to evaluate the diagnostic accuracy of myocardial ischemic memory and its spatial extent using 3D speckle-tracking echocardiography. METHODS The left circumflex coronary artery was occluded for 2 min, followed by reperfusion, in 33 dogs. Their hemodynamic and 3D echocardiographic data were chronologically acquired. Peak systolic strain, early systolic strain index as a parameter of ESL, postsystolic strain index as a parameter of PSS, and myocardial dysfunction index as a combined parameter of ESL and PSS were analyzed in all left ventricular segments. RESULTS At the center of the risk area, early systolic strain index and postsystolic strain index significantly increased until 20 min after reperfusion compared with baseline, although peak systolic strain recovered by 20 min. Myocardial dysfunction index significantly increased for >20 min after reperfusion and allowed better diagnostic accuracy of ischemic memory than the other parameters. In the 147 risk segments, abnormal values of myocardial dysfunction index remained in 49 segments (33%) at 20 min after reperfusion, whereas abnormal peak systolic strain was observed in only 13 segments (9%). CONCLUSIONS ESL and PSS persisted after transient ischemia and could be detected by 3D speckle-tracking echocardiography. Integrated analysis of ESL and PSS provided higher diagnostic accuracy of ischemic memory. This method may be useful for detecting transient ischemic insults in patients after the disappearance of anginal attack.

中文翻译：

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使用三维斑点跟踪超声心动图评估心肌缺血性记忆：早期收缩期延长和收缩期缩短后的新型综合分析。

背景技术短暂缺血后微妙的异常心肌变形如收缩后缩短（PSS）的持续存在可用于诊断心肌缺血的历史（心肌缺血记忆）。此外，早期收缩期延长（ESL）作为心肌缺血的另一个标志物最近引起了人们的关注。但是，尚不清楚是否可以通过三维（3D）散斑跟踪超声心动图检测到这种异常变形的持续性，与二维超声心动图相比，该方法具有相对较低的时空分辨率。这项研究的目的是使用3D斑点跟踪超声心动图评估心肌缺血性记忆的诊断准确性及其空间范围。方法对33只犬的左旋支冠状动脉闭塞2分钟，然后再灌注。他们的血液动力学和3D超声心动图数据是按时间顺序获取的。在所有左心室节段中分析了收缩压峰值，收缩压早期指数作为ESL的参数，收缩压后应变指数作为PSS的参数以及心肌功能障碍指数作为ESL和PSS的综合参数。结果在危险区域的中心，尽管收缩压峰值在20分钟后恢复，但与基线相比，早期收缩压指数和收缩后应变指数直到再灌注后20 min仍显着增加。再灌注后> 20分钟，心肌功能障碍指数显着增加，并且与其他参数相比，缺血性记忆的诊断准确性更高。在147个风险片段中，再灌注后20分钟，心肌功能障碍指数的异常值仍保留在49个片段中（33％），而仅在13个节段（9％）中观察到异常的峰值收缩压。结论短暂性脑缺血后ESL和PSS持续存在，可以通过3D散斑跟踪超声心动图检测到。ESL和PSS的集成分析可提高缺血性记忆的诊断准确性。该方法可用于检测心绞痛发作消失后患者的短暂性缺血性损伤。