The mechanism underlying sudden death from electric shock.

Much has been written on the effects of electric shock on the body. However, in those cases in which victims become pulseless and therefore die suddenly, the underlying event has assuredly been ventricular fibrillation. In this condition of the heart, all of the muscle fibers of the ventricles, the main pumping chambers, contract and relax randomly and pump no blood. Simple protracted cardiac arrest, in this circumstance, is most unlikely. It generally is believed that only low-frequency alternating current can induce ventricular fibrillation; this assumption is invalid, because a single pulse of current applied to the body, as well as high-frequency current, can induce ventricular fibrillation. The important variables are the type and magnitude of the current and the manner in which it is applied to the body. To date, the current pathway has received too little attention. This article reviews the various mechanisms by which a single shock or a train of pulses can induce ventricular fibrillation.