1, athletes heart syndrome: long-term exercise cardiac adaptive changes, the ST – T changes are mostly in the Ⅱ, Ⅲ, aVF leads and anterior chest leads, can be coronal T wave, easy to misdiagnose as myocarditis and coronary artery disease. Long-term exercise, good cardiac function, exercise or isoprenaline can make the ST-T change to normal, which can help to differentiate. 2, persistent juvenile (infantile) type T wave: TV1 to V4 inversion, deep inspiration or oral potassium salt can make the T wave become upright. The incidence is 0.5% to 4.2% in normal people, and it is common in people with collapsed chest wall. 3, apical phenomenon: manifested as TV4 (or TV5) inversion, right lateral recumbency can make the T wave to upright. It is mostly seen in lean and long-bodied young people, and may be related to the contact between the apical and chest wall or pressure interference with myocardial repolarization. 4, two-and-a-half syndrome: in normal people, especially long and lean body type can occasionally be seen in the frontal QRS – T angle increased, QRS electrical axis pointing + 90 °, and T electrical axis pointing – 30 °, like clock 02:30. manifested as II, III, aVF leads in the QRS wave main wave up, T wave inverted; exercise test or oral potassium salt can make the T wave back to upright help to identify. 5, cardiovascular neurosis: often manifested in the Ⅱ, Ⅲ, aVF leads in the T wave hypotonic, inverted (can be accompanied by ST segment downward shift), taking insulin can be restored to normal. Common in young and middle-aged women, with clinical manifestations of autonomic dysfunction. 6, upright T wave abnormalities: performance in the Ⅱ lead T wave inversion in the upright position, shallow or return to upright when lying down, taking insulin can prevent the occurrence, may be related to sympathetic excitation when standing. 7, hyperventilation T wave changes: hyperventilation (tens of seconds) in the anterior thoracic leads after a one-time occurrence of T wave hypoplasia, inverted, taking the T-an can prevent such T wave changes. Hyperventilation in healthy people about 11% can cause T-wave changes, some people think it may be related to sympathetic excitation early cause ventricular muscle uncoordinated repolarization. 8, postprandial T-wave changes: T-wave hypotonic inversion in leads Ⅰ, Ⅱ and V1~V4 after meal, fasting or meal with potassium salt 3g can eliminate or prevent this T-wave change, some people think it may be related to postprandial blood potassium reduction. Although the above T-wave changes are not pathologically significant, they are easily misdiagnosed.