Department of Medicine, Sørlandet Hospital Arendal, Arendal, Norway.
J Am Soc Echocardiogr. 2011 Oct;24(10):1118-25. doi: 10.1016/j.echo.2011.06.002. Epub 2011 Jul 18.
Early prediction of infarct size directs therapy in patients with acute myocardial infarction (AMI). Global strain by echocardiography describes myocardial deformation and correlates with infarct size. However, peak strain measures deformation at a single time point, whereas ischemia and necrosis influence deformation throughout the heart cycle. It was hypothesized that the measurement of myocardial deformation throughout the heart cycle by mean strain is a more comprehensive expression of myocardial deformation. The aim of this study was to assess the ability of mean strain to predict infarct size and to identify large infarctions at admission and after revascularization in patients with AMI.
Seventy-six patients with AMI were included. Echocardiographic measurements were performed at admission and after revascularization. Myocardial strain was calculated using speckle-tracking echocardiography. Infarct size was measured using contrast-enhanced magnetic resonance imaging ≥3 months after revascularization.
There were significant correlations between infarct size and longitudinal global mean strain, longitudinal global strain, and left ventricular ejection fraction (P < .0001), both at admission and after revascularization. The correlations improved after revascularization. Longitudinal global mean strain had the best correlation with infarct size and the best ability to discriminate between different infarct size categories. At admission, a cutoff value of -7.6 had 89% sensitivity, 88% specificity, and an area under the receiver operating characteristic curve of 0.92 for the identification of large infarctions. Prediction of infarct size improved for all parameters after revascularization.
Longitudinal global mean strain provides improved early prediction of infarct size in patients with AMI compared with longitudinal global strain and left ventricular ejection fraction.
早期预测梗死面积可指导急性心肌梗死（AMI）患者的治疗。超声心动图的整体应变描述了心肌变形，并与梗死面积相关。然而，峰值应变仅在单个时间点测量变形，而缺血和坏死会影响整个心动周期的变形。研究假设通过平均应变测量整个心动周期的心肌变形是心肌变形的更全面表达。本研究旨在评估平均应变预测梗死面积的能力，并在 AMI 患者入院和血运重建后识别大面积梗死。
共纳入 76 例 AMI 患者。在入院时和血运重建后进行超声心动图测量。使用斑点追踪超声心动图计算心肌应变。在血运重建后≥3 个月使用对比增强磁共振成像测量梗死面积。
梗死面积与入院时和血运重建后的纵向整体平均应变、纵向整体应变和左心室射血分数呈显著相关（P<0.0001）。血运重建后相关性得到改善。纵向整体平均应变与梗死面积相关性最好，对不同梗死面积类别的鉴别能力最强。入院时，-7.6 的截断值对大面积梗死的识别具有 89%的敏感性、88%的特异性和 0.92 的受试者工作特征曲线下面积。所有参数在血运重建后预测梗死面积的能力均得到改善。
与纵向整体应变和左心室射血分数相比，纵向整体平均应变可提供 AMI 患者更早期的梗死面积预测。
