Objective:To investigate the value of echocardiography combined with ECG T wave amplitude in the evaluation of left ventricular systolic function in dilated cardiomyopathy (DCM).Methods:Eighty patients diagnosed with DCM in our hospital from April 2018 to December 2022 were selected as subjects, and were divided into NYHA Class Ⅱ group (n=28), NYHA class Ⅲ group (n=26) and NYHA class Ⅳ group (n=26) according to New York College of Cardiology (NYHA) cardiac function grade.??All patients underwent echocardiography and simultaneous 12-lead combined table electrocardiogram.??Spearman rank correlation was used to analyze the correlation between T-wave amplitude of echocardiography and electrocardiogram and severity of DCM cardiac function classification.??ROC curve was used to analyze the diagnostic efficacy of echocardiography combined with T-wave amplitude of electrocardiogram in evaluating left ventricular systolic function of DCM. Results:LVESV, LVESD, LVEDV and LVEDD in NYHA Ⅲ and Ⅳ groups were higher than those in NYHA Ⅱ group, and the difference was statistically significant (P < 0.05).?LVESV, LVESD, LVEDV and LVEDD in NYHA grade Ⅳ group were higher than those in NYHA grade Ⅱ and NYHA grade Ⅲ groups, and the difference was statistically significant (P<0.05).?LVEF in NYHA Ⅲ and Ⅳ groups was lower than that in NYHA Ⅱ group, and the difference was statistically significant (P < 0.05).??The LVEF of NYHA grade Ⅳ group was lower than that of NYHA grade Ⅱ and NYHA grade Ⅲ groups, and the difference was statistically significant (P<0.05).?The T wave amplitude of ECG in NYHA Grade Ⅱ, NYHA Grade Ⅲ and NYHA grade Ⅳ groups decreased gradually at the II, V4, V5 and V6 leads, and the decrease was most obvious in NYHA grade Ⅳ group, the difference was statistically significant (P<0.05).??Echocardiogram parameters LVESV, LVESD, LVEDV, LVEDD were positively correlated with the severity of cardiac function classification in DCM patients (r=0.486,0.514,0.473, 0.522, all P<0.001).?There was a negative correlation between LVEF and severity of cardiac function classification in DCM patients (r=0.504, P<0.001).Ecg T-wave amplitude was negatively correlated with severity of cardiac function classification in II, V4, V5, V6 leads (r=0.438,0.465,0.530, 0.512,all P<0.001).?Echocardiography combined with ECG T-wave amplitude had a higher diagnostic value for left ventricular systolic function of DCM (AUC=0.922, 95%CI: 0.845-0.998, P<0.001), which was significantly better than that of echocardiography alone (AUC=0.863, 95%CI:??0.7577-0.970, P<0.001) and ECG T-wave amplitude alone in the diagnosis of left ventricular systolic function in DCM (AUC=0.706, 95%CI: 0.560-0.853, P=0.024)?.Conclusion:Echocardiography combined with electrocardiogram T-wave amplitude can be used as an important index to evaluate left ventricular systolic function in DCM, and provide reference for clinical treatment.