Epidemiology of cardiac arrest and resuscitation in a suburban community.

A surveillance system identified all out-of-hospital victims of cardiac arrests who received emergency aid in King County, Washington, as well as the etiologic condition and cardiac rhythm causing each arrest. During an 18-month period, 649 cardiac arrests occurred (annual incidence 7.2/10,000). Primary heart disease was the cause in 81%. Ventricular fibrillation was the associated rhythm in 57% of cardiac arrests. Based upon the incidence of cardiac arrest in the community and the likelihood of resuscitation under optimal conditions, we estimate the maximum incidence of lives saved to be 2.0/10,000 annually.