Defibrillators are devices that send an electrical pulse or shock to restore a normal heartbeat. There are several types including manual external, manual internal, semi-automated external, automated external, implantable cardioverter defibrillator, and wearable cardiac defibrillator. Defibrillators are used to treat life-threatening cardiac dysrhythmias like ventricular fibrillation and pulseless ventricular tachycardia. Nurses play an important role in responding to cardiac emergencies by maintaining airway and ventilation, applying monitor leads and pads, starting IV access, administering medications, and delivering electrical shocks with defibrillators.