Abstract: To investigate the application value in diagnosis and prognosis evaluation of echocardiography and dynamic electrocardiogram examination in patients with acute myocardial infarction(AMI), 100 AMI patients admitted and diagnosed in our hospital from June 2016 to June 2018 were selected as the observation group, and 100 patients without coronary heart disease in the same period were selected as the control group. Cardiac death was the end point of AMI, the observation group was divided into death group (n=15) and survival group (n=85). All patients were underwent echocardiography examination by Philips IU-Elite and EPIQ5 color Doppler ultrasound, as well as the dynamic electrocardiogram examination by the standard 12 lead Holter performed with DMS-300 4A electrocardiograph. The changes of heart rate turbulence index[TO, TS], heart rate variability index[SDNN, QTd, QTcd], and cardiac function index[LVEDD, LVEF] levels in each group were compared. The results showed that the TO, QTd, QTcd and LVEDD in the observation group were significantly higher than those in the control group, while TS, SDNN and LVEF were significantly lower than those in the control group (P<0.05). TS and SDNN in death group were significantly lower than those in survival group (P<0.05). The TO of death group was higher than that of survival group, while the QTd, QTcd, LVEF and LVEDD of death group were lower than those of survival group, but there was no significant difference (P>0.05). This study demonstrated that, HRT in patients with AMI decreased or even disappeared, HRV and LVEF decreased, LVEDD and QTd increased, and the QT interval prolonged. The echocardiography combined with dynamic electrocardiogram examination has important clinical value in the diagnosis and prognosis evaluation of patients with AMI.

Key words: acute myocardial infarction(AMI), echocardiography, dynamic electrocardiogram, heart rate turbulence(HRT), heart rate variability, cardiac function