Objective To evaluate left ventricular functional changes before and after exercise in patients with suspected coronary heart disease （CHD） using echocardiographic left ventricular strain combined with stress echocardiogra- phy test.Methods A total of 118 subjects with suspected coronary heart disease were enrolled. Based on the results of coronary artery imaging examinations, they were divided into a coronary artery stenosis group (83 cases) and a control group (35 cases). The control group consisted of individuals whose coronary artery imaging results ruled out the presence of coronary artery stenosis. All subjects underwent stress echocardiography (SE) within one week. Echocardiographic analysis involved measuring left ventricular global longitudinal strain (GLS). The Disease group was further subdivided based on coronary angiography findings into mild (n=27), moderate (n=32), and severe (n=24) stenosis groups. The following parameters were assessed: changes in left ventricular ejection fraction (LVEF) and global longitudinal strain from rest to peak exercise, as well as the sensitivity and specificity of exercise global longitudinal strain for predicting coronary stenosis. Results The controlled and mild stenosis groups demonstrated contractile reserve, indicated by a statistically significant increase in LVEF during stress compared to rest (P＜0.05). In contrast, the moderate and severe stenosis groups showed no contractile reserve, with no significant change in LVEF from rest to stress (P＞0.05). At rest, peak global longitudinal strain was normal in the controlled and mild stenosis groups but reduced in the moderate and severe stenosis groups. At peak exercise, global longitudinal strain was significantly lower than resting values in the moderate and severe stenosis groups (P＜0.05), whereas it was significantly higher than baseline in the controlled and mild stenosis groups (P＜0.05). Exercise global longitudinal strain showed high sensitivity and specificity for predicting coronary stenosis.Conclusion Echocardiographic left ventricular strain analysis combined with a stress echocardiography test provides a quantitative assessment of myocardial function in patients with suspected CHD, enhancing the diagnostic value of echocardiography