Abstract: Objective:To explore the effects of emergency percutaneous coronary intervention(PCI) and selective PCI on left ventricular function and prognosis of patients with acute myocardial infarction(AMI).Methods:The first AMI 43 patients treated without vein thrombolysis were selected,29 patients were treated with emergency PCI(emergency group),and 14 cases were treated with selective PCI(selective group).All patients were examined using transthoracic echocardiography(TTE) before PCI,and after 1 and 3 months of PCI,and the levels of left ventricular end diastolic diameter(LVEDD),left ventricular end systolic diameter(LVESD),left ventricular end diastolic volume(LVEDV),left ventricular end systolic volume(LVESV) and left ventricular ejection fraction(LVEF) were measured in wo groups.Results:The success rates of operation in two groups were 100%.The stent was implanted into the stenosis location of coronary artery in patients treated with PCI,and the success rate of stent implanting was 100%.Compared before operation,the levels of LVEDD,LVESD,LVEDV and LVESV decreased,and the level of LVEF significantly increased in emergency group after 1 and 3 months of operation(P<0.05 to P<0.01).Compared before operation,the levels of LVEDD,LVEDV and LVESV decreased(P<0.05 to P<0.01),the level change of LVESD was not obvious(P>0.05),and the level of LVEF significantly increased in selective group after 1 and 3 months of operation(P<0.01).The differences of the levels of LVEDD,LVESD,LVEDV and LVESV between two groups before operation were not statistically significant(P>0.05),and the levels of LVEDD,LVESD,LVEDV and LVESV in emergency group were lower than those in selective group after operation(P<0.05).Conclusions:Emergency PCI can improve the reconstruction of left ventricular,and inhibit the left ventricular systolic function in AMI patients.The treatment effect of emergency PCI on AMI is significant.