Defibrillator. Defibrillators are devices that supply a voltage charge to the heart in the hope of r

Defibrillator. Defibrillators are devices that supply a voltage charge to the heart in the hope of restarting the cardiac cycle (heartbeat). (a) A portable automated external defibrillator (AED). The unit includes two paddles that are pressed against the external chest wall, which deliver a brief voltage charge from a generator to the patient. AEDs are given credit for saving thousands of lives every year, mainly from sudden cardiac arrest (SCA). (b) An implantable cardioverter defibrillator. ICDs are used during surgery and may be inserted for postsurgical maintenance.