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In the clear

In the wake of the massive snowstorm that swung through the eastern U.S. this past weekend, there is no question that hospitals from Ohio to Maine saw a jump in cardiac related emergencies. It happens every winter: People go out to shovel a walkway, their heart rate soars (as high as 175 beats per minute), and if they overdo the shoveling (especially if they’re unaware of hidden cardiac problems), many times the result is a heart attack or a sudden cardiac arrest (SCA).

We’ve all seen TV shows where doctors yell, “Clear!” while using a defibrillator to administer an electric shock to a patient suffering cardiac arrest. Until recently, the only place to receive that life-saving shock was on an operating table or in an ambulance. But thanks to an advanced technology, and to the efforts of the Red Cross, defibrillators have taken on a new life outside the operating room, as automated external defibrillators (AED). With the possibility of saving an estimated 50,000 lives a year, this is an important tool that everyone needs to be aware of.

Synching the shock

Sudden cardiac arrest occurs when the ventricles of the heart begin to contract chaotically and fall out of synch with their normal rhythm. Blood flow to the body is halted and within five seconds the victim loses consciousness. Because the chance of survival decreases quickly for each minute that treatment is delayed, only about five percent of SCA victims survive. But if cardiopulmonary resuscitation (CPR) and defibrillation are administered quickly following the onset of attack, chances for survival rise dramatically.

In the past, the use of a defibrillator required a medical professional trained to interpret heart rhythms in order to administer the shock at just the right moment. In automated external defibrillators, embedded computer chips recognize the rhythms so that even those who are untrained can use the device without causing accidental shock.

The American Heart Association has now included AED use in what is called the “chain of survival” for cardiac arrest. The four links in the AHA chain:

  • Call 911
  • Begin CPR
  • Restore heart rhythm with defibrillator
  • Get advanced care from a medical professional
If all of these steps were quickly followed at the onset of each cardiac arrest, the estimated 1,000 daily SCA victims worldwide would have far better chances of survival.


Protecting the good Samaritan

Since they were first introduced in the mid-1990’s, the use of AEDs has steadily grown, largely due to a campaign by the Red Cross to promote their installation in public places such as airports, airliners, shopping centers, casinos, athletic clubs, beaches – just about anyplace where people congregate in large numbers.

Based on several studies that have clearly demonstrated the effectiveness of AEDs in saving lives, Congress passed the Cardiac Arrest Survival Act two years ago, requiring that AEDs be installed in all federal buildings in the U.S., making quick defibrillation available to more than one million federal workers. The Act also provides what are known as “good Samaritan” protections to make any person who provides emergency care with an AED free of liability for civil damages.

Even though AEDs are simple enough to be operated by just about anyone, training is recommended to improve response time and to make the general public aware of the special needs of SCA victims. American Red Cross chapters throughout the U.S. offer Workplace Training programs for both large and small businesses. Trainers can be scheduled to visit worksites where they instruct employees on both AED use and CPR in a single training session. To find out more about this program, or to schedule training for yourself personally, contact your local Red Cross chapter, or visit their web site at

Wave of the future 

Automated external defibrillators are also available for home use for those who are at high risk of SCA: Patients who have already survived a cardiac arrest or heart attack, and anyone with other heart related problems such as angina or heart disease. At present, you can only buy an AED with a doctor’s prescription, but efforts are underway to drop this unnecessary requirement. After all, if AEDs are freely available to anyone in an airport – they should also be freely available to anyone in their own home. The catch is: they’re not free. Far from it. In fact, some models run well over $1,000 dollars. But some AED suppliers offer leasing plans with monthly payments.

In addition to the concerted efforts of the Red Cross, there’s another strong indicator that we’ll be seeing more and more AEDs in use as time goes by: The National Institutes of Health has devoted $18 million for a Home AED Trial (HAT) that will involve 7,000 subjects. Recruitment for this study is still underway, so if you or someone you know would like information about participating, you can visit the website for the Seattle Institute for Cardiac Research at

I believe that in just a few years, the use of automated external defibrillators will be as common as CPR and the Heimlich maneuver. But AEDs are only as useful as the good Samaritans who are called on to operate them. You can help promote AED training by talking to your employer about the Red Cross Workplace Training program. And if you forward this e-Alert to family members and friends, you’ll help make more people aware that in the time it’s taken to read this message, a life may have been saved with a well-timed shock to the heart.

To Your Good Health,

Jenny Thompson
Health Sciences Institute

“Public Use of Automated External Defibrillators” New England Journal of Medicine, Vol. 347:1242-1247, 10/17/02
“Use of Automated External Defibrillators by a U.S. Airline” New England Journal of Medicine, Vol. 343:1210-1216, 10/26/00
“Automated External Defibrillators Save Lives!” Red Cross of Central Maryland
“American Red Cross Applauds Passage of Cardiac Arrest Survival Legislation” American Red Cross, Press Release, 10/27/00
“What is Sudden Cardiac Arrest? Neal, Kuhn and Huffsteder, Safety/Risk Management Consultants
“A Shock at Home Can Save Your Life” Harvard Heart Letter, 2/1/03