Speckle-tracking echocardiography correctly identifies segmental left ventricular dysfunction induced by scarring in a rat model of myocardial infarction
Speckle-tracking echocardiography correctly identifies segmental left ventricular dysfunction induced by scarring in a rat model of myocardial infarction
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DOI：
10.1152/ajpheart.01176.2006
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发表时间：
2007-06-01
影响因子：
4.8
通讯作者：
Penn, Marc S.
中科院分区：
文献类型：
--
作者：
Popovic, Zoran B.;Benejam, Carlos;Penn, Marc S.
斑点追踪超声心动图（STE）使用二维超声心动图图像来估计两个正交的应变分量。本研究的目的是评估周向（S-circ）和径向（S-rad）应变对大鼠心肌梗死诱导的左心室（LV）去碘化和左心室瘢痕形成的敏感性。探讨S-circ、S-rad之间的关系。在34只刘易斯大鼠结扎左前降支4 ~ 10周后，收集瘢痕大小的二维超声心动图LV短轴图像（12 MHz换能器，Vivid 7回波机）。通过Masson三色染色的组织学LV横截面评估节段性纤维化百分比。10只正常大鼠作为超声心动图对照。STE评估S-circ和S-rad。组织学数据显示，前节和外侧节的瘢痕形成一致，并向后节和下节延伸。脑梗死后S-eire和S-rad均显著降低（P < 0.0001）。如预期的那样，S-circ和S-rad在梗塞节段中最低。多元线性回归显示节段性S-circ同样依赖于节段性纤维化和收缩末期直径（两者P < 0.0001），而节段性S-rad测量更依赖于收缩末期直径（P < 0.0001）而不是纤维化百分比（P < 0.002）。STE正确识别大鼠心肌梗死后瘢痕形成诱导的节段性LV功能障碍。
Speckle-tracking echocardiography (STE) uses a two-dimensional echocardiographic image to estimate two orthogonal strain components. The aim of this study was to assess Sensitivity Of circumferential (S-circ) and radial (S-rad) strains to infarct-induced left ventricular (LV) reniodeling and scarring of the LV in a rat. To assess the relationship among S-circ, S-rad. and scar- size, two-dimensional echocardiographic LV short-axis images (12 MHz transducers, Vivid 7 echo machine) were collected in 34 Lewis rats 4 to 10 wk after ligation of the left anterior descending artery. Percent segmental fibrosis was assessed front histological LV cross sections stained by Masson trichrome. Ten normal rats served as echocardiographic Controls. S-circ, and S-rad were assessed by STE. Histological data showed consistent scarring of anterior and lateral segments with variable extension to Posterior and inferior segments. Both S-eire and S-rad significantly decreased after invocardial infarction (P < 0.0001 for both). As anticipated S-circ and S-rad were lowest in the infarcted segments. Multiple linear regression showed that segmental S-circ were similarly dependent on segmental fibrosis and end-systolic diameter (P < 0.0001 for both), whereas segmental S-rad measurements were more dependent on end-systolic diameter (P < 0.0001) than on percent fibrosis (P < 0.002). STE correctly identifies segmental LV dysfunction induced by scarring that follows myocardial infarction in rats.