Abstract: Objective:To explore the clinical significance of the QRS distortion of the terminal portion of ECG detection in determining the prognosis of patients with acute myocardial infarction(AMI).Methods:The AMI patients were divided into group A and group B according to the patients with the presence and absence of terminal QRS distortion in the first-time ECG diagnosis.The prognosis between two groups were compared after the same treatment.Results:Seventy-five percent patients with smoking history,62.5% of patients with angina pectoris history in A group were found,which was significantly higher than those in group B(37.5% and 25.0%)(P<0.01).The incidence of ventricular arrhythmia in group A(47.0%) was higher than that in group B(18.8%)(P<0.01).The left ventricular ejection fraction in group A(43±12)% was less than that in group B(53±11)%(P<0.01).Conclusions:The terminal QRS distortion in ECG diagnosis can be served as an important index in the evaluation of prognosis of AMI patients,which can make more scientific and accurate evaluation of prognosis.