What is an AED?

Posted by: Lubas Medical on 17th July 2018

Defibrillation is the delivery of electrical energy to the heart during an abnormal rhythm or very rapid erratic beating of the heart known as Ventricular Fibrillation (VF).  Electrodes placed on the victim’s chest to serve as the conduit for delivering a measured electrical shock to the heart to restore natural rhythm.


The first use of an external defibrillator on a human was in 1947 by Claude Beck.

The portable version of the defibrillator was invented in the mid-1960s by Frank Pantridge in Belfast, Northern Ireland, a pioneer in emergency medical treatment

How does it work?

Automatic external defibrillators, or AEDs, are small computerized devices that analyze heart rhythms and provide the shock needed for defibrillation.

Through electrodes placed on a patient’s chest a processor inside the AED analyzes the victim’s heart.

The machine will not shock unless it is necessary; AEDs are designed to shock only when VF, a common cause of cardiac arrest, is detected.

After the AED analyzes the heart rhythm and determines a shock is required, an electric current is delivered to the heart through the victim’s chest wall through the adhesive electrode pads.

The shock delivered by a cardiac defibrillator interrupts the chaotic rhythm and allows it to return to normal.

What’s the difference?

With CPR alone, the chance of survival after sudden cardiac arrest is less than 5%; when CPR is combined with the use of a cardiac defibrillator within the first few minutes, the chance of survival can increase dramatically to more than 75%.

Having an AED on hand gives victims of sudden cardiac arrest the best chance of survival until paramedics arrive and take over care.