UW News

January 23, 2003

Automatic defibrillator machines now available for home use

You slept well, but you’re feeling weighed down by crushing fatigue, then by intense chest pain. You kind of lose track of events after that, because your heart goes into something called ventricular fibrillation, meaning that instead of a steady beat of contractions, it begins to quiver and your pulse stops while your blood pressure falls to zero.

Fortunately, your nearest and dearest sees you collapse. He or she calls 911 and pulls the automatic external defibrillator (AED) out of a kitchen cabinet, turns it on, and follows the instructions provided by its electronic voice.

The AED, recently approved for home use by the Food and Drug Administration, has been touted as the next essential home appliance. Dr. Mickey Eisenberg, director of emergency medicine services at UW Medical Center, says it may not be for every household.

“If your doctor has told you that you have heart disease or is treating you for heart disease caused by atherosclerosis or coronary heart disease, you can be considered at risk,” Eisenberg says. “This is the most common form of heart disease, the one that kills about 750,000 Americans, both men and women, every year. The key point is that if you can deliver a shock to the heart within two to four minutes after ventricular fibrillation starts, the person has an excellent chance of full recovery and many more years of life.

“This event happens in hearts that are too good to die. If you can stop this fatal rhythm with an electric shock, the person has many miles left on the tire.”

Eisenberg says that using an AED requires almost no training, since it is designed to help the user through the event.

“Once the machine is turned on, it coaches you through every step of the procedure,” Eisenberg says. “It will tell you everything to do and when you’ve completed a step, it will move on to the next one.”

Some people worry about children injuring themselves by playing with AEDs, but the machine will only deliver a shock when it detects ventricular fibrillation, not when it detects either a normal heart rhythm or no heart beat.

“If you were to apply an AED to someone whose heart was beating normally, it would not deliver a shock –- it wouldn’t be able to,” Eisenberg says.

In the case of ventricular fibrillation, though, an AED can spell the difference in survival for a heart patient.

“There is no question that the chance of administering a successful shock in these situations falls at a rate of about 5 to 10 percent a minute. That’s why in most of this country, almost everyone dies who develops this condition,” Eisenberg says. “By the time the event is recognized, help is summoned by phone and arrives, even in the best circumstances, it’s been eight minutes, and the chance of survival is remote. If that shock is given by a partner or spouse in two to three minutes, then we’re talking about a meaningful chance of resuscitation.”

Eisenberg, a long-time emergency room physician with no financial interest in the companies marketing AEDs, points out that you must have a doctor’s prescription to purchase an AED and that the cost, currently over $1,500, is not covered by most health insurance plans.

“A young person in good health without underlying heart disease has a miniscule chance of this fatal event happening. I don’t believe he or she needs a device like this,” Eisenberg says. “However, if the person has documented heart disease, then it’s worth discussing with a doctor.”