AED machine

Synonyms: Automated external defibrillator, Defibrillator

Medical Specialties: Cardiology, Emergency medicine, Internal medicine

Clinical Definition

An AED machine is a portable medical device that can be used to treat life threatening arrhythmias, including pulseless ventricle tachycardia and ventricular fibrillation. The machine is programmed to analyze myocardial rhythms and if indicated, deliver a therapeutic dose of electrical energy to the heart. The electrical current depolarizes a critical mass of the myocardium and terminates the arrhythmia in order to restore an effective heart rhythm.  

In Our Own Words

An AED machine is a device that can deliver an electrical shock in order to treat abnormal heart rhythms. In some instances, the heart can start beating chaotically, which does not allow blood to be pumped effectively to the brain or other vital organs. An AED machine can administer a shock that interrupts the chaotic heart rhythm and allows the heart to beat effectively.


The machine is designed to be used by anyone, including those without medical training. Electrode pads are placed on the chest of the patient and the machine then analyzes the heartbeat. If the heart rhythm requires a shock, a volt of electricity can be administered to the patient.


AED machines are increasingly commonplace in busy, public areas, including shopping malls, businesses, airports, convention centers, hotels, stadiums and schools.

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  • National Heart, Lung and Blood Institute. “What is an Automatic External Defibrillator?” Accessed September 2013.
  • American Red Cross. “Learn About Automatic External Defibrillators.” Accessed September 2013.
  • American Heart Association. “What is an Automatic External Defibrillator?” Accessed September 2013.
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