Objectives To detect and compare the systolic strain rate (SR) and strain in the infarct and ischemic myocardium by strain rate imaging (SRI), in order to explore the clinical value of SRI in evaluating regional left ventricular systolic dysfunction. Methods Patients with coronary artery disease were divided into angina pectoris (11 cases) and myocardial infarction (21 cases) groups. Twenty age-matched normal subjects served as the control group. Septal, lateral, anterior, inferior, anteroseptal and posterior walls of the left ventricle were respectively scanned using color tissue Doppler imaging (TDI). Then SR and strain curves were derived from TDI for basal, middle and apical segments of each wall. SRI parameters were: Systolic SR (SRsys), systolic strain (εsys) and maximum strain (εmax). Results Compared with normal segments, SRsys, εsys and εmax decreased significantly in the infarct and ischemic segments (P<0.01). Compared with ischemic segments, SRsys, εsys and εmax decreased significantly in the infarct segments (P<0.05). Conclusions SRsys, εsys and εmax measured by SRI can be used to quantitatively analyze regional left ventricular systolic dysfunction in patients with coronary artery disease, and aid in differentiating infarct from ischemic myocardium. Objectives To detect and compare the systolic strain rate (SR) and strain in the infarct and ischemic myocardium by strain rate imaging (SRI), in order to explore the clinical value of SRI in evaluating regional left ventricular systolic dysfunction. Methods Patients with coronary artery The lesions were divided into angina pectoris (11 cases) and myocardial infarction (21 cases) groups. Twenty age-matched normal subjects served as the control group. Septal, lateral, anterior, inferior, anteroseptal and posterior walls of the left ventricle were respectively scanned using color tissue Doppler imaging (TDI). Then SR and strain curves were derived from TDI for basal, middle and apical segments of each wall. SRI parameters were: Systolic SR (SRsys), systolic strain (εsys) and maximum strain (εmax) . Results Compared with normal segments, SRsys, εsys and ε max decreased significantly in the infarct and ischemic segments (P <0.01). Compared with ischemic segments, SRsys, εsys and εmax decrea The values ​​of ssss and εmax measured by SRI can be used to quantitatively analyze regional left ventricular systolic dysfunction in patients with coronary artery disease, and aid in differentiating infarct from ischemic myocardium.