Objective To investigate the value of two-dimensional speckle tracking imaging（2D-STI） combined with real time three-dimensional echocardiography（RT-3DE） in evaluating left ventricular function after percutaneous coronary intervention（PCI） in patients with acute myocardial infarction.Methods A retrospective analysis of 30 patients with acute myocardial infarction underwent PCI was performed.Left ventricular function and synchrony were evaluated by 2D-STI and RT-3DE before treatment

1 week and 1 month after operation.The 2D-STI left ventricular function indexes included the longitudinal strain（LS） of the left ventricular basal

apical

and middle segments

the left ventricular global longitudinal strain（GLS）

and the synchronization indexes included the maximum-minimum difference of the peak time of the 18 segments（Tp-diff） and standard deviation（Tp-SD）.RT-3DE left ventricular function indexes included basal segment

middle segment

apical segment ejection fraction（EFbase

EFmiddle

EFapex） and left ventricular ejection fraction（LVEF）

and the synchronicity indexes included the time at which 16 segments reach the minimum systolic volume maximum-minimum difference（Tmsv-16-diff） and standard deviation（Tmsv-16-SD）

and the percentage of the two cardiac cycles after correction by RR interval（Tmsv-16-diff%

Tmsv-16-SD%）.ROC curve was drawn to analyze the diagnostic efficiency of 2D-STI

RT-3DE and their combination in left ventricular asynchromy.Results The results of 2D-STI showed that the GLS

basal segment LS

apical segment LS and middle segment LS were gradually increased

and the difference between 1 month and 1 week after operation were statistically significant（all P<0.05）.The Tp-diff and Tp-SD were decreased

and the differences were statistically significant between 1 week after operation and before operation

and between 1 month and 1 week after operation（both P<0.05）.The results of RT-3DE showed that the LVEF

EFbase

EFmiddle and EFapex were gradually increased

and the difference between 1 month and 1 week after operation were statistically significant（all P<0.05）.The Tmsv-16-diff

Tmsv-16-SD

Tmsv-16-diff% and Tmsv-16-SD% were gradually decreased

the differences of Tmsv-16-diff

Tmsv-16-diff% were statistically significant between 1 week after operation and before operation

and between 1 month and 1 week after operation（both P<0.05）.The differences of Tmsv-16-SD

Tmsv-16-SD% were statistically significant between 1 month and 1 week after operation（both P<0.05）.ROC curve analysis showed that the area under the curve of 2D-STI and RT-3DE in diagnosis of left ventricular synchronization were 0.869 and 0.878

the sensitivity were 91.35% and 92.24%

and the specificity were 79.23% and 76.67%

respectively.The sensitivity and specificity of the combined application were 96.88% and 81.35%

the area under the curve was0.968

which was higher than that of 2D-STI and RT-3DE（Z=4.945

P<0.05）.Conclusion 2D-STI combined with RT-3DE can assess left ventricular systolic and synchrony in patients with acute myocardial infarction

and plays an important guiding role in clinical treatment.