There is a strong correlation between the time till defibrillation with a defibrillator and survival in cases of ventricular fibrillation occurring out-of-hospital. In Sweden, it takes on average 14 minutes from cardiac arrest till defibrillation. The goal is to reduce this time to 5 minutes.

A huge effort is currently being made to distribute defibrillators to the community. It is important to study the consequences of this.

The present study is based on the following issues:

1. The proportion of cases of ventricular fibrillation in Sweden where a defibrillator is used before the ambulance arrives will gradually increase because of an increasing distribution of defibrillators to the community.
2. Survival among these patients will be higher than for other patients with ventricular fibrillation.

All patients with ventricular fibrillation in the Swedish registry of cardiac arrests out-of-hospital from 1 January 2008 – 31 December 2013 will be surveyed using the questions written above. Both survival and cerebral function are being studied in relation to whether the patient was defibrillated before the ambulance arrived, and if so, by whom.