Objective To explore the clinical application value of two-dimensional speckle tracking echocardiography（2 D-STE） in the differential diagnosis of ischemic dilated cardiomyopathy（IDCM） and nonischemic dilated cardiomyopathy（NIDCM）.Methods According to the results of coronary angiography

41 IDCM patients and 43 NIDCM patients were taken as the research groups

and 24 normal patients were taken as the control group.Conventional ultrasound examination was performed

left ventricular ejection fraction（LVEF）

left ventricular end-diastolic diameter

interventival septal thickness and left ventricular posterior wall thickness were obtained.The left ventricular global longitudinal strain（GLS）

global circumferential strain（GCS）and global radial strain（GRS） of each group were measured by 2 D-STE.The above parameters among groups were compared.Receiver operating characteristic（ROC） curve was drawn to differentiate NIDCM from IDCM.Results LVEF in the IDCM group was significantly lower than that in the NIDCM group（P<0.05）

and there were no statistically significant differences in other conventional ultrasound parameters between the two groups.GLS in the IDCM group and NIDCM group was lower than that in the control group（both P<0.05）

but GLS between the NIDCM group and the IDCM group was no significant difference.GCS and GRS in the NIDCM group were significantly lower than those in the IDCM group [（-5.4±2..6）% vs.（-7.0±2.5）%

（7.5±4.5）% vs.（10.7±4.7）%

both P<0.05].The results of ROC curve demonstrated that the GRS has the largest AUC（AUC=0.701）

with the cutoff 8.5%

the sensitivity 66%

and the specificity 74%.In addition

the AUC of GLS was 0.525

with the cutoff-10.1%

the sensitivity 51%

and the specificity 63%.The AUC of GCS was 0.688

with the cutoff-6.7%

the sensitivity 65%

and the specificity 68%.And the AUC of LVEF was 0.620

with the cutoff 33.5%

the sensitivity 51%

and the specificity 72%.Conclusion The left ventricular myocardial strain of IDCM and NIDCM patients are significantly decreased

and GRS could be used to help differentiate NIDCM from IDCM.