Defibrillation.

Defibrillation has emerged as the single most effective intervention for resuscitation of patients from cardiac arrest. This article reviews the electrophysiologic basis of defibrillation, and ways to increase the effectiveness of counter-shocks, particularly for refractory ventricular fibrillation. Automatic implantable and automatic external defibrillators have been developed and are being used in many locations. In future years they will be used increasingly in the homes of high-risk patients, in community settings with limited access to emergency care, and by minimally trained pre-hospital emergency personnel.