QRS wide malformations can be caused by cardiac surgery, cardiac catheterization, severe myocarditis, congenital heart disease, infection, hypoxia, and electrolyte disturbances. However, in many cases, the cause is not easily determined. So how to make a diagnosis? Please see the following explanation. Diagnosis 1, the ventricular rate is often between 150-250 beats/min, QRS wave is wide and deformed, the time limit is widened. 2, T wave direction is opposite to the main wave of QRS waveless, and there is no fixed relationship between P wave and QRS wave. 3, Q-T interval is mostly normal, can be accompanied by Q-T interval prolongation, mostly seen in polymorphic ventricular tachycardia. 4.The letter rate is slower than the ventricular rate, and sometimes ventricular fusion waves or ventricular seizure can be seen. ECG features: a. Three or more ventricular preterm contractions appear consecutively. b, QRS wave group morphology is abnormal, the time limit is more than 0.12 seconds, and the ST-T wave direction is opposite to the main direction of the QRS wave group. c. The ventricular rate is usually 100-250 beats/min, and the rhythm is regular, but it can also be irregular. d. Independent atrial activity is not fixed in relation to the QRS wave group, forming a ventricular-atrial separation; occasionally, individual or all ventricular excitations reverse to capture the atria. e. The attack usually starts suddenly. f. Ventricular seizure and ventricular fusion waves: A few supraventricular impulses can travel down to the ventricles during ventricular tachycardia episodes, producing ventricular seizure, which is manifested by a normal QRS wave group occurring after the P wave and before the burst. The QRS wave pattern of ventricular fusion wave is between sinus and ectopic ventricular beats, which means partial ventricular seizure. The presence of ventricular seizure and ventricular fusion wave provides an important basis for establishing the diagnosis of ventricular tachycardia. The presence of ventricular capture and ventricular fusion waves is important in establishing the diagnosis of ventricular tachycardia.