A defibrillator is any device used in the defibrillation of the heart muscle. It is made up of the main unit and is equipped with a set of two electrodes. The electrodes are placed directly on or in the patient. In the case of an internal implanted defibrillator, the entire device is placed inside the body, whereas, with an external defibrillator, defibrillation is carried out externally by placing the electrodes, or "pads", at different points on the torso of the victim or patient.

A defibrillator delivers an electric shock to the heart muscle in an attempt to reintroduce a normal heart rhythm to a someone who has suffered or is suffering cardiac arrest. Cardiac arrest, or sudden cardiac arrest (SCA,) occurs due to "ventricular fibrillation". This is simply a situation in the heart in which an electrical "short-circuit" has occurred, causing the heart muscle to " fibrillate" or quiver. The short-circuiting of the hearts electrical system causes a distortion in the coordinated contractions of the heart muscle causing it to fibrillate.

Having a heart in this condition means little or no forward bloodflow is extant in the body, leading to circulatory arrest followed quickly by death. The brief time span between the onset of cardiac arrest and the death of the victim is the main reason that currently less than 5% of people who suffer sudden cardiac arrest do not live through it.

Defibrillators have been around in crude form since the 1940s. In fact the first life saved using a defibrillator was in 1947, when Claude Beck successfully revived a young patient using an open-chest defibrillation device. Since the 1980's though the science has been evolving into a very precise and technically efficient system. Internal and external defibrillators are now far safer and more efficient than they ever have been.

AED's or "automated external defibrillators" are now even available to the public. They are becoming more visible in public gathering places such as theatres, sports stadiums, churches, etc. They are also employed by the travel industry, being found in the cockpits of commercial airliners, on cruise ships, and in other transport related industries. The reason lies in the fact that portable defibrillators are now capable of audibly and visually taking a non-trained individual step-by-step through the entire defibrillation process.

Defibrillators for home use are also becoming more common. In the same way that commercial companies are using them, defibrillators are being employed in homes around the US, especially by those who suffer from, or have family members who suffer from, heart related illness. This is an encouraging step forward technologically and medically. With growing numbers of people having available to them this life-saving device, the rate at which sudden cardiac arrest claims its victims may soon be seen to be in decline.

So, if you haven't already, take a look at the growing number of AED's now available. Having a defibrillator available in a home or office, more especially if someone there has a heart condition, is worth all the life insurance you could ever buy. And the new breed of defibrillator can be picked up for a song.

One caveat: for most home use defibrillators you will need a doctor's prescription. The Philips Heart Start Home edition is currently the one exception, but that may change in time.