The most common cause of cardiac arrest is ventricular fibrillation, in which the ventricles of the heart contract in a rapid and uncoordinated way. While irregular heartbeats occur occasionally in most people, the heart usually re-establishes its regular heart rhythm. When it doesn't this can turn into an emergency situation. Cardiac arrest occurs because the heart muscle just basically quivers and does not pump any blood through the circulatory system. The victim will collapse and lose consciousness, pulse and blood pressure would not be detected. If let untreated the victim would be clinically dead within 3 - 5 minutes. If emergency treatment is delayed beyond 3 minutes, the victim may be revived but may suffer from permanent brain damage.
Several new studies have shown the effectiveness of having portable automated external defibrillators available in public places where cardiac arrest can occur. One study placed these devices in a casino and trained casino security officers to use these devices. During the study the guards observed nearly 150 cases of cardiac arrest, using defibrillators on 105 whose cardiac arrest was caused by ventricular fibrillation. More than half of those treated by the security guards survived to hospital discharge. Further the study showed that almost 75% of those who were treated within three minutes of their collapse survived to hospital discharge as compared to only half of those shocked after more than three minutes. Another study done placing the devices on American Airlines flights and training the airline flight crews in their use yielded only slightly lower results. The difference may be in time to transport to hospital.
In both studies the researchers also noted that training both casino security guards and airline crews was relatively easy, and that both performed well in treating the cardiac arrest victims.
The units used in both studies are much different than the defibrillators one sees in hospitals or on "ER". While made by several different manufacturers, they are very similaer. They weigh about 4 pounds and are fully automated for use by trained non-medical personnel. The unit will not allow a shock to be administered unless it detects ventricular fibrillation. Despite what is shown on television, patients who are "flatlining" are not candidates for shock, it is only administered when ventricular fibrillation is detected. The shock can often "reset" the electrical impulses of the heart and convert the heart to a normal rhythm.
The FDA approved these devices for airline use in 1996, and in 1998 a law was passed relinquishing liability for both airlines and for medically qualified passengers administering the procedure. As one of the researchers said "These devices are so simple that even an untrained volunteer could likely operate them successfully." Most states have passed laws also to protect those administering the procedure from liability, and further have recommended the placement of these devices in places where they could save lives, places such as amusement parks, police cars and airports, train stations even some large shopping malls.
If you have had a heart attack, remember you are at much higher risk for developing a life threatening cardiac arrhythmia. The risk also increases with age. If these devices are available, you and other victims of cardiac arrest have a much greater chance of recovery and return to normal functioning.
Updated 11/08/05
As of January 1, 2004 Medicare covers automated external defibrillators and wearable defibrillators for specified at-risk patients. It would need to be prescribed by a physician and meet the guidelines for coverage. There is also one automated external defibrillator (Phillips HeartStart Home Defibrillator) that has been approved by the FDA for purchase without a prescription.
