AEDs: High-Tech Help for Cardiac Arrest


Technology has given us the automated external defibrillator (AED). This is a small, lightweight, battery operated, portable defibrillator. You may see these devices in schools and public buildings, airports, malls, sports arenas, health clubs, golf courses, and some businesses.

Automated external defibrillator machine on wall.

Defibrillation is needed when a heart starts to beat abnormally, and so fast that very little blood can be pumped out to the body. An AED uses an electric shock to help the heart return to its normal rhythm.

Here are some FAQs to help bring you up to speed.

What is an automated external defibrillator?

The automated external defibrillator (AED) is a computerized medical device. It's battery powered with adhesive defibrillator pads that are applied to the chest to allow an electrical current to pass through to the heart to reset the heart's normal electrical current. A normal, regular or organized electrical rhythm through the heart is necessary for the muscle to contract and pump blood to the body.

When a person is in cardiac arrest, they have either no electrical current, a rapid rhythm that doesn't allow for the heart pumping chambers to fill properly (ventricular tachycardia), or a disorganized electrical rhythm or current that doesn't allow the heart muscle to contract and circulate blood to the body (ventricular fibrillation). Ventricular fibrillation and ventricular tachycardia can be stopped with an electric shock to restore normal heart rhythm and circulation to the body. This is called either cardioversion or defibrillation.


AEDs are very accurate and easy to use. There are many different brands of AEDs, but the same basic steps apply to all of them. The American Heart Association doesn't recommend a specific model.

Do you need training to use an AED?

No. Most anyone with or without a medical background can learn to use an AED or apply the pads properly and administer a shock by following the prompts provided by the AED. Usually, people learn to use an AED in a course that also teaches CPR. The computerized device will tell a rescuer to push the defibrillate button if cardiac arrest is from an abnormal heart rhythm that could respond to a shock. (Not all rhythms will.) This could be either ventricular fibrillation or ventricular tachycardia. Ventricular fibrillation is the most common heart-rhythm problem in victims of sudden cardiac arrest.


No. The cost of AEDs has decreased a lot in the past few years. Many of these devices and the replacement components cost about $1500 to $2000. 

Are AEDs really needed in places other than hospitals?

The rate of sudden cardiac death can be reduced by placing AEDs in the community and by teaching people how to use them. Seconds and minutes count when cardiac arrest occurs. The likelihood of survival decreases for every minute that goes by without this type of help.

Is an AED useful for all types of cardiac arrest?


Do AEDs mean CPR is no longer needed?


Does research back the community use of AEDs?


Online Medical Reviewer: Louise Cunningham RN BSN
Online Medical Reviewer: Ronald Karlin MD
Online Medical Reviewer: Steven Kang MD
Date Last Reviewed: 9/1/2020