What is an Automated External Defibrillator?

How does an Automated External Defibrillator (AED) work?

How the shock fixes Sudden Cardiac Arrest (SCA).

Who can use an AED?

Why you should have an AED in your facility?

Isn't calling 911 enough?

AED Demo Video

Chain of Survival.

What is an Automated External Defibrillator?
An AED is a small, portable device that analyzes the heart's rhythm and prompts the user to deliver a defibrillation shock if it determines one is needed. Once turned on, the AED guides the user through each step of the defibrillation process by providing voice and/or visual prompts.

AEDs are specially designed for easy use by a "first responder," who would be the first person to typically arrive on the scene of a medical emergency. A first responder can be an emergency medical services worker, a firefighter or police officer, or it can be a layperson with minimal AED training.

Time to defibrillation, the most critical factor in sudden cardiac arrest (SCA) survival, can be reduced if an AED is "on-site" and can be brought to the victim quickly. This is one of the reasons that survival rates improve in communities with active AED programs. Remember, every minute that passes before defibrillation reduces survival rates by 7 to10 percent.

The goal is to improve SCA survival rates.

How does an AED work?
Once an AED is turned on, it provides prompts to guide the user through the process. One of the first prompts instructs the user to connect the AED to the victim via the adhesive electrodes (pads) placed on the chest.

The AED then analyzes the victim's heart rhythm through the electrodes using a built-in computer program. It then determines if a shock is "needed" or "necessary." More specifically:

1. The electrodes placed on the victim's body send the heart rhythm information (ECGs) to the AED.
2. The AED "reads" short segments of the heart's rhythm. It checks characteristics such as frequency, shape, slope, amplitude and heart rate.
3. Based on these characteristics, the AED determines whether or not a shock is needed and activates the appropriate user prompts.

How the shock fixes SCA
The delivery of an electrical shock to a heart experiencing SCA briefly stops all electrical activity in the heart. This brief "break" from the previous electrical chaos can be enough for the heart to restart beating with a normal rhythm.

Not everyone can be saved from SCA even with defibrillation. But early defibrillation, especially when delivered within three minutes of a person's collapse from SCA, does provide the best chance.

Who can use an AED?
Almost anyone can learn to operate an AED with a few hours of training-no medical background is needed to use an AED. In fact, the American Heart Association says, "AEDs are sophisticated, computerized devices that are reliable and simple to operate, enabling lay rescuers with minimal training to administer this lifesaving intervention" (a defibrillation shock), and "flight attendants, security personnel, sports marshals, police officers, firefighters, lifeguard, family members, and many other trained laypersons have used AEDs successfully."1

AEDs are designed to help people with minimal training safely use them in tense, emergency situations. They have numerous built-in safeguards and are designed to deliver a shock only if the AED detects that one is necessary.

Their ease of use and built-in safety mechanisms make AEDs suitable for use in community or company-wide programs

You can help create a Heart Safe Community by learning to use an AED and/or helping to place AEDs in public places.

1 "Guidelines 2000 for Cardiovascular Resuscitation and Emergency Cardiovascular Care," Circulation. 2000;102(8): (suppl l): I-60

Why you should have an AED in your facility?
Early defibrillation with an on-site AED can be the difference between life and death.

The time to the first defibrillation shock is the most critical factor in determining survival rates for sudden cardiac arrest (SCA). With every minute that goes by, survival rates decrease by about 10%. That leaves a window of ten minutes in which to potentially save your life or the life of someone you know, after which survival rates average less than 2%.

The best results for defibrillation occur in the first three minutes, measured from the moment the victim collapses to when the defibrillation shock is delivered. On average, it takes EMS teams in the U.S. an average of 6 to 12 minutes to arrive.

That's why having an AED readily accessible wherever groups of people gather makes good preventive sense.

Isn't calling 911 enough?
Emergency medical service (EMS) professionals and firefighters save many SCA victims each year, but a lack of equipment and time delays keep them from saving many more.

Lack of equipment - Unfortunately, not every emergency vehicle carries a defibrillator, the only device that can treat sudden cardiac arrest.

Lack of time - In some large metropolitan areas, an ambulance may not even get to the scene in less than 10 minutes due to traffic. And, on average, it takes EMS teams in the U.S. 6 to12 minutes to arrive. So, even if an EMS team does have a defibrillator, the response time may not be fast enough to save a victim's life.

The Revive & Survive Program is made possible by a grant from NCHS to the Kathryn Weil Center for Education