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Automated External Defibrillator (AED)

AED (Automated External Defibrillator) Pronunciation: A-E-D (ā-ē-dē)

Definition: An AED is a portable electronic device that automatically diagnoses and treats life-threatening cardiac arrhythmias, such as ventricular fibrillation or pulseless ventricular tachycardia, through the application of electrical therapy, allowing the heart to reestablish an effective rhythm.

What is an Automated External Defibrillator (AED)?


An AED is used during a life-threatening event called sudden cardiac arrest, typically caused by an arrhythmia such as ventricular fibrillation. The device analyzes the heart’s rhythm and delivers a shock if necessary, to restore a normal heart rhythm.

Key Facts about Automated External Defibrillators (AEDs):

  • AEDs are designed to be used by non-medical individuals in emergency situations. They provide voice prompts and visual instructions so that virtually anyone can use them.
  • AEDs detect ventricular fibrillation or ventricular tachycardia, life-threatening heart rhythms that can result in sudden cardiac arrest. If the device detects one of these rhythms, it delivers an electric shock to the heart, with the goal of restoring a normal heart rhythm.
  • Early defibrillation, alongside CPR, is a critical part of the chain of survival in cardiac arrest. For every minute delay in defibrillation, the survival rate decreases by about 10%.
  • Many public places, including airports, schools, and offices, now have AEDs readily available in case of emergency.
  • While AEDs are designed to be safe and easy to use, formal training in their use is recommended to increase comfort and efficiency.

Automated External Defibrillator (AED) Usage & Maintenance

How to use an AED?

AEDs are designed to be user-friendly. They provide clear voice commands and simple illustrations to guide users through the process.

  • Turn on the AED.
  • Expose the person’s chest and attach the adhesive pads as depicted in the device’s instructions.
  • Stand clear and let the device analyze the person’s heart rhythm.
  • If the device advises a shock, ensure no one is touching the person and then press the shock button.

Check out this short introduction video on how to use an AED:

Maintaining an AED

AEDs require routine maintenance, including regular checks for battery life and pad expiry, to ensure they are ready to use in an emergency.

Frequently Asked Questions About AEDs

How does an AED work?

An AED works by analyzing the victim’s heart rhythm and delivering an electric shock, if needed, to restore the heart’s normal rhythm. The device provides audio and visual instructions, guiding the user through the process.

When should an AED be used?

An AED should be used when someone is experiencing sudden cardiac arrest, unresponsive, and not breathing or gasping for air. It is crucial to use the device as soon as possible to increase the chances of survival.

Can anyone use an AED?

Yes, AEDs are designed for use by untrained individuals as well as healthcare professionals. The device provides step-by-step instructions to guide the user in administering the treatment.


  1. American Red Cross. (n.d.). What is an AED? Retrieved May 27, 2023, from
  2. American Red Cross. (n.d.). AED program for organizations. Retrieved May 27, 2023, from
  3. Mayo Clinic. (2023). Automated external defibrillators: Do you need an AED? Retrieved May 27, 2023, from