超声斑点追踪技术对猪心肌挫伤前、后左室短轴二维应变的研究

目的:运用斑点追踪技术(STI)测量猪闭合性心肌挫伤前、后左心室短轴各节段的二维应变值,观察正常人室壁二维应变的规律,探讨斑点追踪技术对节段性心肌缺血的临床应用价值。方法:采用小型撞击器对9只贵州小型巴马猪进行撞击建立闭合性心肌损伤模型,记录猪撞击前及撞伤后左室短轴观3个水平的高帧频图像,应用二维应变分析软件测量各节段的径向应变(RS)、圆周应变(CS)。结果:闭合性心肌挫伤前Rs在同一水平各节段间差异无统计学意义,乳头肌水平显著高于心尖水平(P<0.05);Cs在同一水平不同节段间差异有统计学意义(P<0.05)。闭合性心肌挫伤后的挫伤节段的Rs和Cs显著低于正常组相应节段(均为P<0.01、P<0.05)。结论:STI能够准确测量左室短轴各节段的二维应变值、敏感评价心肌缺血程度。

Left ventricle short axis two-dimensional strain in pigs with myocardial contusion measured by speckle tracking imaging echocardiography

Objective:To evaluate the clinical value of speckle tracking echocardiography for the measurement of two dimensional strain echocardiography(2D-SE) technique in pigs with close myocardial contusion and to estimate the left ventricle function of close myocardial contusion.Methods:9 small Guizhou-Panama pigs were used.The close myocardial contusion animal mode,was snccessfully set up using the small impactor.High frame rate two-dimensional images were recorded from the left ventricular short-axis views at three different levels before and after the MC.Radial strain(RS) and circumferential strain(CS) were measured in the left ventricular short-axis views using 2DS strain analysis software.Results:2DS analysis software showed that there was no significant difference(P>0.05) of the RS at the same levels mentioned above in left ventricle before the MC.RS and CS after the strike were significantly decreased compared with pre-myocardial contusion(P<0.05,P<0.01) at the same levels mentioned above in left ventricle.Conclusion:Speckle tracking imaging echocardiography(STI) could be used to precisely quantify different levels in the left ventricular short-axis views using 2DS technique.2DS is a new method to estimate the myocardial ischemia ventricle function rapidly,accurately and sensitivity.