What is an AED?
An automated external defibrillator (AED) is a lightweight, portable device that delivers an electric shock through the chest to the heart.
The shock can stop an irregular rhythm and allow a normal rhythm to resume in a heart in sudden cardiac arrest.
Sudden cardiac arrest is an abrupt loss of heart function. If it’s not treated within minutes, it quickly leads to death.
Most sudden cardiac arrests result from ventricular fibrillation. This is a rapid and unsynchronized heart rhythm starting in the heart’s lower pumping chambers (the ventricles).
The heart must be “defibrillated” quickly, because a victim’s chance of surviving drops by 7 to 10 percent for every minute a normal heartbeat isn’t restored.
Why are AEDs important?
AEDs make it possible for more people to respond to a medical emergency where defibrillation is required. Because AEDs are portable, they can be used by nonmedical people. They can be made part of emergency response programs that also include rapid use of 9-1-1 and prompt delivery of cardio pulmonary resuscitation (CPR). All three of these activities are vital to improving survival from cardiac arrest.
How does an AED work?
A built-in computer checks a victim’s heart rhythm through adhesive electrodes. The computer calculates whether defibrillation is needed. If it is, a recorded voice tells the rescuer to press the shock button on the AED. This shock momentarily stuns the heart and stops all activity. It gives the heart the chance to resume beating effectively. Instructions guide the user through the process.
Who can use an AED?
Ideally, everyone would receive training on the use of an AED. Unfortunately, most people's first interaction with an AED occurs during a life or death situation when a co-worker, friend, or passerby suffers cardiac arrest. So people without a medical background are encouraged in a crisis to respond by opening the AED, following the instructions and administering the necessary treatment. Most states have Good Samaritan Laws that protect laypersons offering emergency aid.
Are AEDs safe to use?
AEDs are safe to use. Studies have shown that 90 percent of the time AEDs are able to detect a rhythm that should be defibrillated. And 95 percent of the time they are able to recommend NOT shocking when the computer shows defibrillation is not indicated.