Division of Functional Diagnostics, Department of Health Sciences, Osaka University Graduate School of Medicine, Suita, Japan.
Division of Functional Diagnostics, Department of Health Sciences, Osaka University Graduate School of Medicine, Suita, Japan.
J Am Soc Echocardiogr. 2019 Nov;32(11):1477-1486. doi: 10.1016/j.echo.2019.06.013. Epub 2019 Aug 26.
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.
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.
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%).
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.
短暂缺血后持续存在细微的异常心肌变形，如收缩后缩短（PSS），可用于诊断心肌缺血（心肌缺血记忆）。此外，最近人们关注到早期收缩期伸长（ESL）作为另一种心肌缺血标志物。然而，与二维超声心动图相比，空间和时间分辨率相对较低的三维（3D）斑点追踪超声心动图是否能检测到这种异常变形的持续存在尚不清楚。本研究旨在评估 3D 斑点追踪超声心动图诊断心肌缺血记忆及其空间范围的准确性。
33 只狗的左回旋支冠状动脉闭塞 2 分钟，随后再灌注。它们的血流动力学和 3D 超声心动图数据按时间顺序采集。分析所有左心室节段的峰值收缩应变、早期收缩应变指数（ESL 的参数）、收缩后应变指数（PSS 的参数）和心肌功能障碍指数（ESL 和 PSS 的综合参数）。
在危险区中心，与基线相比，尽管 20 分钟时峰值收缩应变恢复，但早期收缩应变指数和收缩后应变指数在再灌注后 20 分钟内显著增加。心肌功能障碍指数在再灌注后 >20 分钟显著增加，对缺血记忆的诊断准确性优于其他参数。在 147 个危险节段中，再灌注后 20 分钟时，心肌功能障碍指数异常值仍存在于 49 个节段（33%），而只有 13 个节段（9%）出现异常峰值收缩应变。
短暂缺血后 ESL 和 PSS 持续存在，可通过 3D 斑点追踪超声心动图检测。ESL 和 PSS 的综合分析提供了更高的缺血记忆诊断准确性。这种方法可能有助于检测心绞痛发作消失后患者的短暂性缺血损伤。
