Objective To assess the clinical values of the longitudinal strain delay index(LSDI) and the delay of time in peak anterospetal wall to posterior wall strain(TAS-POST),which are analyzed by speckle tracking imaging,was discussed in the article.Methods The study included 39 patients with acute myocardial infarction,37 patients with coronary heart disease but not acute myocardial infarction which was confirmed by selective coronary angiography and 30 age-gender-related volunteers.Two-dimensional echocardiography was performed to collect dynamic images of left ventricular apical long axis view,two-chamber view,four-chamber view and parasternal short axis mitral view,papillary view and apical view.The time to minimal systolic longitudinal,radial,circumferential strain (Tssl,Tssr and Tssc) were measured from the start point of QRS wave of electrocardiogram.The left ventricular segmental standard deviation (Tssl-SD,Tssr-SD,Tssc-SD) and maximal difference (Tssl-Dif,Tssr-Dif,Tssc-Dif) were calculated.The left ventricular dyssynchrony was defined as TAS-POST≥130 ms and LSDI≥25%.Results The dyssynchrony parameters in the acute myocardial infarction group were significantly increased compared to the control group ( P <0.001 or P <0.05 ).The parameters in the myocardial ischemia group were also higher than those in the control group ( P <0.05).Linear regression showed that LSDI was positive correlated with TAS-POST( r =0.676,P <0.05).In acute myocardial infarction group,LSDI was more sensitive in the detection of left ventricular dyssynchrony than TAS-POST ( P < 0.05 ).Conclusions Left ventricular dyssynchrony can be evaluate accurately by speckle tracking imaging.LSDI and TAS-POST are quantitative parameters for the evaluation of left ventricular dyssynchrony in coronary heart disease. Key words: Echocardiography; Coronary diseases; Ventricular function,left; Speckle tracking imaging