T-wave hypoplasia in V5V6 lead refers to an abnormality in the process of myocardial repolarization in V5V6 lead. On the ECG, there are P waves, QRS waves, and T waves, in which the T wave is flush with the horizontal line of the ST segment without significant elevation or inversion, which is called T wave hypoplasia.T wave hypoplasia is an electrocardiographic phenomenon, which can be seen in the normal population or non-cardiac diseases, including electrolyte disorders, neurological abnormalities, effects of medications, and perimenopausal period. It can also be seen in a variety of heart diseases, such as coronary heart disease, myocardial ischemia, myocarditis, cardiomyopathy and so on. Therefore, the presence of T-wave flattening is not equal to myocardial ischemia or coronary heart disease, but also need to be combined with other clinical data to make a comprehensive and accurate judgment. If there is any ECG abnormality, it is recommended to go to the Department of Cardiovascular Medicine of the regular hospital.