The automated external defibrillator (AED) has seemingly popped up every place where people gather over the last decade. Schools, airports, sporting arenas, stores, and city buildings across the country now have a clearly marked AED available to anyone who may experience a sudden cardiac arrest. However, defibrillation is neither new nor novel.
But before we get into that, first it is important to…
Before we can uncover the definition of Defibrillation, it is important to know what fibrillation is. A normal, healthy heart uses the body’s natural electricity to cause it to contract. Just like any muscle in the body, the heart alternately contracts and relaxes, but unlike your biceps or calf muscles, the heart contracts and relaxes without you having to think about it. This process that began long before you were born will continue until the day you die. When there is an interruption in the electrical impulse that controls the muscle contractions in the heart, the heart begins to quiver rather than beat. As a result, blood cannot efficiently enter or leave the heart. This quivering is called fibrillation.
A (Very) Brief History of Defibrillation
Research into defibrillation began just before the turn of the 19th centuries when two physiologists, Jean-Louis Prévost and Frédéric Batelli discovered that small, short electrical shocks could induce fibrillation in dogs. This discovery carried over to William Kouwenhoven’s research, and in 1930 he invented the first external device that would jump-start the heart. After years of testing the device on dogs, it was first used on a human in 1947 by Claude Beck to save the life of an otherwise 14-year-old boy who was in ventricular fibrillation.
Over time the defibrillator became a standard piece of equipment in hospitals everywhere but was not intended for use by non-medical personnel. In fact, the first pre-hospital defibrillation did not happen until ambulance physicians performed one in 1966. The first defibrillation that was conducted without the presence of physicians occurred in 1969.
Fast Forward to Today
While manual defibrillators are still the standard of care in hospitals and other medical settings for their versatility, AEDs have become more common where non-medical personnel would have a need for them. AEDs include picture instructions for electrode placement, verbal instructions for use and sometimes even video demonstrations to follow as the AED is deployed. They are also equipped with safety protocols that keep them from being used when they are not necessary.
If a person collapses from sudden cardiac arrest, one bystander can begin CPR while another finds the closest AED. Defibrillator pads that deliver the electrical charge are placed in two places on the person’s chest, and the power button is pressed. If the AED is fully automated, a life-saving protocol will begin with clear audio signals. If the AED is partially automated, it will require the user to press a “shock” button when instructed to.
The likelihood of surviving a sudden cardiac arrest is dramatically improved if bystanders begin CPR and administer shock via an AED. Although defibrillation is not new, the AED’s prevalence in our society is a welcome advancement.