QT interval shortening of ECG refers to the time between Q wave and T wave of ECG is shorter than the normal value range. Normal adult heart rate is 60~100 beats/minute, and the corresponding value of QT interval is 0.44s~0.36S , generally accelerated heart rate will cause QT interval shortening. If it is mild, it has little effect on the body, but pathologic QT interval shortening can affect the patient’s health and even endanger life. QT interval shortening can be divided into secondary QT interval shortening and idiopathic QT interval shortening. 1. Secondary QT interval shortening is commonly seen in hyperkalemia, hypercalcemia, after cardiopulmonary resuscitation, etc. It may also be caused by catecholamines such as dopamine, epinephrine, or digitalis intoxication, which needs to be actively treated according to the cause. 2. Idiopathic QT interval shortening is a hereditary disease caused by a single gene mutation. In mild cases, there may be no obvious symptoms, or only palpitations, dizziness and other symptoms, but some patients have more serious conditions, and fainting, ventricular tachycardia, or even sudden cardiac death may occur at the onset of the disease. Electrocardiogram suggesting a significant shortening of the QT interval should be taken seriously, and timely consultation should be made for further improvement of relevant examinations, assessment and judgment by the doctor, and appropriate treatment should be taken if necessary.