Learn to Use an AED (Automated External Defibrillator)

Medical Author: Melissa Stoppler, M.D.
Medical Editor: Barbara K. Hecht, Ph.D.

AEDs, or automated external defibrillators, are computerized devices that can help prevent death due to sudden cardiac arrest. These devices monitor the heart rhythm and can, if need be, deliver an electric shock to the chest wall much like a traditional (paddle) defibrillator in a hospital. AEDs are now carried on commercial aircraft and are becoming increasingly available at various locations in the community.

Each day about 600 people die in the US of sudden cardiac arrest. The most common cause of sudden cardiac death is an arrhythmia of the heart. Arrhythmias are abnormalities of the heartbeat (severe heart attacks can also lead to cardiac arrhythmias and sudden death).

The arrhythmia that most often causes sudden cardiac death is ventricular fibrillation. It prevents the heart from pumping blood and deprives the body of oxygen. The only way to reverse ventricular fibrillation is defibrillation -- the delivery of an electrical impulse to the heart to restore its normal rhythm.

AEDs are not a substitute for CPR (cardiopulmonary resuscitation). Anyone trained to operate an AED must be trained in CPR, since early CPR is a critical step in resuscitation to help reestablish the circulation of blood and the delivery of oxygen to the body. AEDs may also prompt the rescuer to continue CPR while it is analyzing the heartbeat of the patient.

Medically Reviewed by a Doctor on 12/1/2014