The incidence of out-of-hospital ventricular fibrillation in Helsinki, Finland, from 1994 to 1999.

Early defibrillation by emergency medical services has been a success story in the treatment of ventricular fibrillation. This success has been followed by recommendations to allow public access to defibrillation equipment. We tracked the changes in incidence of ventricular fibrillation from prospectively collected data from the Helsinki Cardiac Arrest Register. We found that the incidence of out-of-hospital ventricular fibrillation of cardiac origin fell by 48% from 1994 to 1999 (p=0.0036). The primary and secondary prevention of coronary artery disease may not be the only reasons for this change and so new public-access defibrillation programmes should be delayed until our findings are confirmed.