Sun Jing Ping, Niu Jianli, Chou David, Chuang Hsuan-Hung, Wang Kai, Drinko Jeanne, Borowski Allen, Stewart William J, Thomas James D
The Cleveland Clinic Foundation, Cleveland, Ohio, USA.
J Am Soc Echocardiogr. 2007 May;20(5):498-504. doi: 10.1016/j.echo.2006.10.029.
Tissue Doppler strain and strain rate imaging have been introduced for quantitative assessment of regional myocardial function. These techniques are largely limited to the evaluation of overall longitudinal myocardial function. This study attempted to apply radial strain, circumferential strain, radial displacement, and strain-based torsion analysis to differentiating the infarct, adjacent, and remote zones in a swine model of myocardial infarction.
Seven pigs, body weight 24 to 26 kg, were subjected to myocardial infarction by occlusion of the left anterior descending coronary artery (LAD) and followed up for 8 weeks. Regional radial and circumferential deformations were quantified noninvasively by ultrasonic strain rate imaging before LAD occlusion, LAD occlusion immediately, and 4, 6, and 8 weeks after LAD occlusion. Strain-based left ventricular torsion was assessed at the same time points.
Both radial and circumferential strains, and torsion, were decreased significantly in the LAD territory areas as a result of myocardial ischemia and infarction. There were no significant changes in radial and circumferential strains, or torsion, in the areas of adjacent and remote zones over time.
These findings demonstrate that speckle-tracking strain imaging may be suitable for noninvasive quantification of left ventricular segmental function of ischemic heart disease.
组织多普勒应变和应变率成像已被用于区域心肌功能的定量评估。这些技术在很大程度上局限于评估整体纵向心肌功能。本研究试图应用径向应变、圆周应变、径向位移和基于应变的扭转分析来区分猪心肌梗死模型中的梗死区、毗邻区和远隔区。
7头体重24至26千克的猪，通过结扎左冠状动脉前降支（LAD）造成心肌梗死，并随访8周。在结扎LAD前、结扎LAD即刻以及结扎LAD后4周、6周和8周，通过超声应变率成像对区域径向和圆周变形进行无创定量。同时在相同时间点评估基于应变的左心室扭转。
由于心肌缺血和梗死，LAD区域的径向和圆周应变以及扭转均显著降低。毗邻区和远隔区的径向和圆周应变以及扭转随时间无显著变化。
这些发现表明，斑点追踪应变成像可能适用于缺血性心脏病左心室节段功能的无创定量。
