An AED is a device that is designed to allow minimally trained people to administer life-saving defibrillation to someone suffering from sudden cardiac arrest (SCA). It analyzes the heart's rhythm for any abnormalities and, if necessary, directs the user to deliver an electrical shock to the person experiencing SCA.
What Is an Automated External Defibrillator (AED)?
An AED is a device with a built-in computer that checks heart rhythm through adhesive electrodes. It’s used to analyze the heart rhythm of someone suffering from SCA, and calculates whether defibrillation (shock) is needed. AEDs are designed to be small and lightweight and can be kept in public places, giving quick access to life-saving techniques for SCA; you do not need to be trained in order to use the AED effectively.
In-hospital defibrillators are manual and larger than AEDs. Only qualified medical personnel with special training should use an in-hospital defibrillator to treat life-threatening heart rhythms. Medical personnel who use the device must decide whether or not to shock the person. Manual defibrillators also have additional capabilities, such as pacing and cardioversion.
Why Would You Need an AED?
Sudden cardiac arrest is an abrupt loss of heart function; if not treated within minutes, it quickly leads to death. Most sudden cardiac arrests result from ventricular arrhythmias, which are rapid and unsynchronized heart rhythms originating in the heart’s lower pumping chambers (the ventricles). The heart must be “defibrillated” quickly, because a victim’s chance of surviving decreases between seven and 10 percent for every minute a normal heartbeat isn’t restored.
How Does an AED Work?
If you’re having a SCA, the person operating the AED will turn it on; the device then prompts the operator to apply two pads to your chest. The AED begins to monitor your heart rhythm through the adhesive electrodes and calculates whether defibrillation is needed. The AED performs an automatic analysis of the rhythm and advises the AED operator of the next step.
If a "shockable" rhythm is detected, a recorded voice tells the operator to press the shock button on the AED. Once the shock button is pushed, the AED administers an electric shock to restore a normal heart rhythm.
The shock momentarily stuns your heart and stops all activity, giving your heart an opportunity to reestablish an effective rhythm. AED shocks are only advised for ventricular fibrillation or another life-threatening condition called pulseless ventricular tachycardia.
What to Expect During Your Automated External Defibrillator
If you experience a sudden cardiac arrest and are admitted to the hospital, you’ll be observed and the medical team will determine the underlying cause of the SCA. Once the cause (such as coronary artery disease) is determined, your heart will continue to be closely monitored, and your candidacy for further treatment will be evaluated. You may be given medicines to try to reduce the chance of another SCA or be considered for an implantable cardioverter defibrillator, if appropriate.