An automated external debrillator (AED) is a lightweight, portable device that delivers an electric shock through the chest to the heart. The shock can stop an irregular heart rhythm and allow a normal rhythm to resume following sudden cardiac arrest. Sudden cardiac arrest is an abrupt loss of heart function. If it’s not treated within minute it will quickly lead to death. Most sudden cardiac arrests result from ventricular debrillation. This is a rapid and unsynchronized heart rhythm starting in the heart’s lower pumping chambers (the ventricles). The heart must be “debrillated” quickly, because a victim’s chance of surviving drops by seven to 10 percent for every minute a normal heartbeat isn’t restored.