Final answer:
Ventricular arrhythmias that require immediate intervention include ventricular fibrillation and ventricular tachycardia. Defibrillation is the most common treatment method used to restore a normal heart rhythm.
Step-by-step explanation:
Ventricular arrhythmias that need immediate intervention include ventricular fibrillation and ventricular tachycardia. Ventricular fibrillation is a life-threatening condition in which the ventricles of the heart quiver and are unable to effectively pump blood. If left untreated for even a few minutes, it can lead to brain death. Immediate treatment for ventricular fibrillation and ventricular tachycardia involves defibrillation, which uses an external electrical shock to restore a normal heart rhythm.