14. Ventricular Fibrillation & Out-of-Hospital Cardiac Arrest

Objective To define the apparent changes in ventricular fibrillation (VF) as cause of out-of-hospital cardiac arrest. (OHCA) Methods Retrospective analysis of prospectively acquired observational data of OHCA in a population-controlled setting with a single emergency medical service (EMS) system between 1991-2004. Results In the study period there were 338 all-cause arrests, with 203 (57%) in homes, 85 (24%) in public locations, and 69 (19%) in other locations (hotels, nursing homes). VF incidence during 1991-1997 was 24/100 000/person-yr and during 1998-2004 it was 11/100 000/person-yr (p<0.001). During 1991-1997, 61/110 (55%) of arrests in homes were in VF and from 1998-2004, 32/93 (34%) were in VF (p=0.003). During 1991-1997 48/51 (94%) of arrests in public places were in VF and from 1998-2004 22/34 (64%) were in VF (p<0.001). Conclusion VF as the cause of OHCA declined dramatically in both home and public settings, both in absolute numbers and in percentage of initial rhythm. This decreased incidence has obvious implications for potential cost-effective and therapeutic benefit from placement of automated external defibrillators.