Automatic External Defibrillators
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 originating 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 AED’s important?
AED’s make it possible for more people to respond to a medical emergency where defibrillation is required. Because AED’s are portable and 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 CPR. Timing is critical when defibrillating (giving a shock) to a patient. If you can administer a shock in 3 minutes from arrest they have a 74% chance of survival, 5 minutes 39%, 10 minutes or longer almost no chance of surviving. Waiting for paramedics is not enough as the average response time in the US is 6-12 minutes. All three of these activities are critical 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 and gives the heart an opportunity to resume beating effectively. Instructions guide the user through the process. AED’s advise a shock only for ventricular fibrillation or another life-threatening condition called pulseless ventricular tachycardia.
Which AED brand should we buy?
There are many AED manufacturers on the market, varying in price and features. Click here to learn more about which AED is right for you.