Abstract: Objective:To investigate the significance of speckle tracing echocardiography in the examination of the rat models of myocardial infarction, and to elucidate the reliability and clinical application of speckle tracing echocardiography in the identification of the myocardial infarction rats. Methods:A total of 50 rats were randonly divided into sham operation group and model group,with 25 rats in each group. Ischemic preconditioning method was used to establish the myocardial infarction models. Speckle tracking echocardiography and cardiac tissue Masson staining were performed to analyze the changes of echocardiography and the morphology of myocardium tissue of the rats. Results:Compared with sham operation group,the each index in echocardiography of the rats in model group before modeling had no significant differences (P>0.05). Compared with sham operation group, the left ventricular ejection fraction (EF), circumferential strain (CS), the peak values of CS in the anterior septum, anterior wall, anterior lateral wall, systolic period, radial strain (RS) of the anterior wall of the rats in model group were decreased(P<0.05); the standardized time to peak of CS of anterior wall(TTP) was increased(P<0.05). The results of Masson staining showed that there was no change in the myocardium tissue and no infarction of the rats in control group;the infarction area of the rats in model group was (4.52±1.41)%;the infarction located in the anterior wall which was the myocardiocyte lesion in the small area. Conclusion:Speckle tracing echocardiography RS and TTP can reveal the infarction area and its surrounding areas of myocardial infarction, and quantitatively detect the myocardial infarction site in the rats. Speckle tracing echocardiography can be used for the clinical rapid diagnosis of myocardial infarction and confirmation of infarction area.

Key words: speckle tracking echocardiography, myocardial infarction, infarction area, cardiac tissue morphology, rats