What is an automated external defibrillator (AED)?
A defibrillator is a device that delivers a jolt of electricity to the patient's chest to correct cardiac arrest and the specific arrhythmias or ventricular fibrillation (irregular heartbeats) that cause the heart's electrical system to malfunction. As multiple parts of the heart's pacemaker begin to beat erratically, the heart cannot rhythmically contract to continue pumping blood throughout the body, which can be fatal if it is not corrected. An automated external defibrillator (AED) is typically used in these situations to deliver a measured electrical shock to the chest cavity using a series of electrodes. The AED shock will stop the heart for just a moment so it can restart its healthy, rhythmic contraction.
However, it's important to note that AEDs can only resuscitate a person if he/she has the specific type of heart rhythm abnormality that AEDs can correct. For instance, a heart attack may lead to sudden cardiac arrest (SCA), but AEDs will have no effect on the blockage in the heart muscle that causes a heart attack. Individuals who are attempting to save a person's life suffering from a cardiac episode should first call emergency services before attempting to administer care. In the vast majority of cases, cardiopulmonary resuscitation (CPR) should be the preferred method to continue the flow of blood to the heart and brain for a short time. If SCA or irregular heartbeats are detected, alternating between the shock of the AED and CPR (between AED charges) is the preferred tactic before emergency services take over.
The value of an AED
In the event of sudden cardiac arrest, the chances of survival with CPR are just 5 percent, but when used in tandem with an AED, the odds of survival jump significantly to 75 percent. Defibrillators were confined to hospitals for much of the 20th century until 1965 when Professor Frank Pantridge from Northern Ireland developed the first portable, battery-powered defibrillator, the predecessor to today's AEDs.
Even though it was bulky and could weigh almost 150 lbs., Pantridge's defibrillator could be transported in an ambulance and gave first responders invaluable extra minutes to administer care and save countless lives in the process. Today, modern AEDs are as ubiquitous as fire extinguishers and found in millions of public places. They are designed for ease of operation so that anyone can provide life-saving care in an emergency situation.