termination of ventricular fibrillation by delivery of an electrical stimulus to the heart, most commonly by applying electrodes of the defibrillator externally to the chest wall but can be performed internally at the time of an open heart surgery or via an implanted device
defibrillator
a device that delivers the electrical stimulus in defibrillation
cardioversion
termination of tachycardia either by pharmaceutical means or by delivery of electrical energy
implantable cardioverter defibrillator (ICD)
an implanted, battery-operated device with rate-sensing leads that monitors cardiac impulses and initiates an electrical stimulus as needed to stop ventricular fibrillation or tachycardia
pacemaker
a device used to treat slow heart rates by electrically stimulating the heart to contract, most often implanted with lead wires and battery circuitry under the skin but can be temporarily placed externally with lead wires inserted into the heart via a vein