Can severe coronary heart disease be detected by electrocardiogram (ECG)?

Severe coronary heart disease typically shows characteristic changes on electrocardiogram (ECG), such as ST-segment depression and T-wave inversion. These changes suggest the possible presence of myocardial ischemia and hypoxia. However, it should be noted that ECG alone cannot directly diagnose coronary heart disease, as abnormal ECG findings may be influenced by multiple factors, and some patients with coronary heart disease may have completely normal ECGs when they are not experiencing an episode. Therefore, for patients suspected of having coronary heart disease, in addition to ECG examination, other clinical information must be considered, including the patient's symptoms, physical signs, medical history, and further tests (such as complete blood count, 24-hour ambulatory ECG, echocardiography, carotid ultrasound, and coronary CTA). The final diagnosis should be made by a qualified physician based on the patient's specific clinical presentation.