An automated external defibrillator (AED) is a portable electronic device. It automatically diagnoses the life-threatening irregular heart rate and rhythm – ventricular tachycardia and fibrillation- and delivers an electric shock (defibrillation) to the heart through the chest to treat them.
Uncoordinated contraction of muscle of the lower chambers (ventricular fibrillation) and dangerously fast heartbeat (ventricular tachycardia) can cause the heart to stop beating (cardiac arrest). Defibrillation stops the irregular rhythm and helps the heart reset into a normal rhythm.
AED is a lightweight, battery-operated, easy to use device. It has simple voice commands and can be used by nonmedical individuals. Variation in heart rhythm is picked up by electrodes in the device and relayed to a built-in computer. If and when defibrillation is needed, a voice command prompts to press the shock button on the AED.