Objective To explore the application value of three-dimensional speckle tracking imaging（3 D-STI）inthe evaluation of left ventricular systolic function in patients with different degrees of aortic stenosis（AS）.MethodsSixty-sixAS patients with normal left ventricular ejection fraction（LVEF）were divided into mild（25 cases）

moderate（21 cases）andsevere（20 cases）AS group.Another 30 healthy volunteers with matched age and sex were selected as control group.Routineechocardiography and 3 D-STI were performed on each group. LVEF

global longitudinal strain（GLS）

global circumferentialstrain（GCS）

global area strain（GAS）and global radial strain（GRS）were obtained

and the results were compared and analyzed.Pearson correlation analysis was used to analyze the correlation between LVEF and strain parameters.ResultsCompared withthe control group

GLS in mild AS group was decreased（P<0.05）

and the differences in GRS

GCS and GAS were notstatistically significant.Compared with control group and mild AS group

GLS and GRS in moderate AS group were decreased

GCS was increased（all P<0.05）

GAS were not statistically significant. Compared with control group

mild and moderate ASgroups

GLS and GRS in severe AS group were decreased

GCS was increased（all P<0.05）

GAS was not statistically significant.Correlation analysis showed that LVEF was positively correlated with GLS

GCS

GAS and GRS（r=0.71

0.59

0.79

0.57

allP<0.01）.ConclusionThe myocardial function has been impaired when AS is mild

and the impairment of cardiac function ismore obvious with the increase of stenosis degree.3 D-STI can be used for early evaluation and has good clinical application value.