How Automated Defibrillators save lives

An automated external defibrillator–AED–is a medical tool designed to analyze the cardiac rhythms of heart attack victims and deliver an appropriate electrical shock to bring the heart’s rhythm back to normal. In other words, they provide a way to instantly respond to cardiac arrest victims and in many cases, save their lives. As a leader in the industry of holter monitors and cardiac monitoring equipment, Cardiac Monitoring Service has put together the following information about automated external defibrillators in an effort to educate the public on these life saving devices.

How Heart Attacks Occur and the Role of Defibrillation

When a heart attack occurs, the blood pumping chambers, or ventricles, fail to work properly, thus blocking oxygen and other nutrients from reaching cells, organs, and other areas of the body. This is called ventricular fibrillation. If immediate blood flow is not restored, death or permanent organ damage can occur. In many cases, the ventricular fibrillation that takes place during a heart attack can be successfully treated by a procedure called defibrillation. The latter is a term that refers to a simple electrical shock applied to the chest area.

Most people who experience a heart attack while in or very near to a hospital survive, as defibrillation can be performed almost at once. However, when cardiac arrest takes place where there is no immediate access to emergency care, the chances of resuscitating the person are very poor. For every 60 seconds that go by with a person in ventricular fibrillation, the chance to resuscitate that person drops by approximately 10 percent. After as little as 10 minutes, the chance of reviving the person is practically zero. Although cardiopulmonary resuscitation– CPR– offers temporary blood circulation and artificial breathing to the patient, it cannot deliver the full levels of oxygen and blood needed by the brain until a defibrillator is used.

Understanding Automated External Defibrillators

At one time, a hospital setting or certain emergency vehicles were the only places in which there was access to an AED and only a trained medical professional could operate such a device. However, in the mid-1980s, medical advancements produced the first computerized defibrillator. This device was the AED, which is capable of interpreting the victim’s cardiac rhythm and delivering the appropriate electrical shock with no input from the operator other than to connect the device and push the button.

Previously, ECG rhythms had to be interpreted before defibrillation could be used, thus shutting out most of the general population from the process. Heart attack victims must still be transported to a hospital following cardiac arrest, but in many cases, AEDs provide those precious few seconds by which the person's life may be saved.

Public Access to AEDs

Because of the scenarios mentioned above, AEDs are regarded by many medical experts as vitally important tools to which individuals need access. These devices are found in many public locations, such as government buildings, schools, community centers and airports, and can be used by the general public. However, the legal regulations associated with the public use of AEDs are still determined on a state-by-state basis.

Depending on the type of medical emergency a person is experiencing, the chances may be very high that he or she can reach a hospital in time to be saved. However, where cardiac arrest is concerned, every minute that passes with a person in a state of ventricular fibrillation reduces that person's chances of surviving and making a full recovery. This is why the widespread placement of automated external defibrillator devices is advocated by many medical experts. 

As a provider of state of the art digital holter monitors, Cardiac Monitoring Service keeps a close eye on the technological advancements that improve heart health. If you have a topic you would like us to cover on a future blog post, drop us a line at