Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, USA.
Ultrasound Med Biol. 2011 Jul;37(7):1073-86. doi: 10.1016/j.ultrasmedbio.2011.04.002. Epub 2011 Jun 2.
This study noninvasively evaluated the development of left ventricular (LV) dyssynchrony following reperfused myocardial infarction (MI) in mice using an ultrasonic speckle-tracking method. Eight C57BL/6J mice were assessed by high-resolution echocardiography at baseline and at eight time-points following MI. Images were acquired at 1mm elevational intervals encompassing the entire LV to determine chamber volumes and radial strain. Receiver-operating characteristic (ROC) analysis of regional radial strain was used to segment the three-dimensional (3-D) LV into infarct, adjacent and remote zones. This in vivo segmentation was correlated to histologic infarct size (R = 0.89, p < 0.01) in a short-axis, slice-by-slice comparison. The onset of dyssynchrony during LV remodeling was assessed by standard deviation of time to peak radial strain in the infarct, adjacent and remote zones. It was discovered that the form of LV dyssynchrony that develops in the remote zone late after MI does so in concert with the progression of LV remodeling (R = 0.70, p < 0.05).
本研究采用超声斑点追踪法非侵入性地评估再灌注心肌梗死后小鼠左心室（LV）不同步的发展。8 只 C57BL/6J 小鼠在基线和 MI 后 8 个时间点通过高分辨率超声心动图进行评估。图像以 1mm 的间隔采集，涵盖整个 LV，以确定腔室容积和径向应变。区域径向应变的接收者操作特征（ROC）分析用于将 3-D LV 分割为梗死、相邻和远程区。在短轴、逐层比较中，这种体内分割与组织学梗死面积相关（R = 0.89，p < 0.01）。通过测量梗死、相邻和远程区径向应变达峰时间的标准差来评估 LV 重构过程中不同步的发生。结果发现，MI 后晚期远程区 LV 不同步的形式与 LV 重构的进展一致（R = 0.70，p < 0.05）。
