Ventricular fibrillation (VF) is the main cause of sudden cardiac arrest. Because the mortality rate of patients with VF is extremely time-dependent, it is essential to perform defibrillation without delay. The automated external defibrillator (AED) is an instrument that laypeople can use anytime and anywhere. We surveyed the installation of AEDs in the 138 hospitals in Nagano Prefecture, and received 113 replies from the 138 hospitals. Fifty-nine hospitals (52%) have installed AEDs. Out of these 59, 28 hospitals experienced 31 events of cardiopulmonary arrest in which AEDs were used in 24 of the events (77%). Ten of 13 patients with VF (77%) were successfully defibrillated. The more the installation rate of AEDs increases and AEDs are popularized, the more likely is the mortality rate to decrease.
