Ventricular tachycardia defibrillation is synchronous electrical defibrillation. The indications for synchronous electrical defibrillation are rapid arrhythmias, where the patient is able to restore sinus rhythm after defibrillation, and the delivery of the resuscitation pulse must be synchronized with the patient’s heartbeat during the electrical shock. The severe arrhythmias that can be treated with synchronized electrical defibrillation are atrial fibrillation, atrial flutter, supraventricular tachycardia, ventricular tachycardia, and other rapid arrhythmias that can be restored to sinus rhythm by electrical defibrillation. In this case, it is important to synchronize the pulse delivery of the resuscitation with the patient’s heartbeat during the electrical shock. This allows the signal of electrical stimulation to fall into the absolute ventricular nonstop period. The indication for desynchronization is fibrillation of the ventricles and is not usually used for ventricular tachycardia, which can result in severe malignant arrhythmias.