Influence of emergency medical services systems and prehospital defibrillation on survival of sudden cardiac death victims.

This article reviews the influence of emergency medical systems and prehospital defibrillation on survival of sudden cardiac death. The historical perspective and epidemiologic considerations of prehospital sudden cardiac death are highlighted. Factors predictive of successful resuscitation and impact of community activity on sudden death are discussed. Influences of emergency medical services on outcome of prehospital cardiac arrest are reviewed, with emphasis on the role of dispatchers, emergency medical technicians, and paramedics. The recent emergence of prehospital automatic defibrillation by emergency medical technicians, first responders, and lay persons is discussed in depth, as it has great potential to positively influence outcome of prehospital sudden cardiac death.