An abnormal ECG T-wave, sinus rhythm, may be a physiologic change or a pathologic change. The normal heart rhythm of human beings starts from the sinus node, so the normal heart rhythm is sinus rhythm. However, T-wave abnormalities in the ECG need to be highly emphasized, which may be physiological changes or disease conditions. T-wave is a wave produced by the ventricles during repolarization, which is affected by external temperature, body type, emotion, exercise status, etc. However, when T-wave abnormality is always present in several ECG examinations, disease-related conditions are often considered first. T-wave abnormality can be low, inverted or hyperacute T-wave. low T-wave suggests mild myocardial insufficiency or myocardial strain, and the patient’s symptoms are atypical. inverted T-wave suggests myocardial insufficiency, and it may be a serious electrolyte disorder. hyperacute T-wave is commonly seen in the super-acute injury stage of myocardial infarction, or hyperkalemia. T-wave abnormalities cannot be diagnosed solely on the basis of ECG results, but should be further clarified on the basis of the patient’s symptoms and signs, combined with other auxiliary tests, such as echocardiography, cardiac function, coronary CT or angiography.