Ventricular tachycardia is a serious arrhythmia that can be seen clinically, usually accompanied by hemodynamic disorders, and may cause sudden death in patients and requires active treatment. Ventricular tachycardia has three main characteristics: 1. The wider the QRS width, the greater the risk of ventricular tachycardia and the greater the possibility of causing ventricular fibrillation or even sudden death in patients. 2. Ventricular fusion waves or ventricular seizure can occur, that is, in wide QRS tachycardia, some of the narrower QRS can be seen. 3. There are free P waves, that is, in tachycardia, P waves with a frequency slower than that of wide QRS tachycardia can be seen.