Giving Emergency Heart Help

It's the size of a laptop computer, weighs less than 10 pounds and can literally zap life back into someone who has collapsed in cardiac arrest. It's an automated external defibrillator, known as an AED.

For anyone who has heart disease or has a loved one who has, AEDs can mean the difference between life and death in a medical emergency. They can help in sudden cardiac arrest, particularly during a heart attack when the heart stops beating properly.

Each minute that treatment is delayed, a person's chance of survival drops by about 10 percent. Within just five minutes, brain damage can be permanent.

Unlike a heart attack, which is caused by blood not reaching the heart, a sudden cardiac arrest means the heart is not able to pump blood effectively. This may occur if the electrical system of the heart stops working, or if the electrical system of the heart, which needs to be in an organized rhythm, becomes chaotic and disorganized. This is called ventricular fibrillation. The most effective treatment is an electric shock to the heart to jolt it back into its regular rhythm. No drug is as effective as electricity in restarting the heart.

AEDs, which deliver those life-saving electric shocks, have made their way into public places, such as airports, casinos, shopping malls, golf courses and sports stadiums, which, according to one research study, make the top 10 list where people are more likely to go into cardiac arrest. Now, the same people who bring you cardiopulmonary resuscitation (CPR) courses are encouraging people to get trained in using AEDs as well.

The heart association hopes that having people better prepared for cardiac emergencies will help change the sad statistics. Each year, nearly 250,000 people die suddenly because of cardiac arrest. Only about 5 percent survive, often because the treatment is provided too late.

When someone collapses, the American Heart Association (AHA) says several emergency actions need to be taken to create a "chain of survival." The links in the chain are:

• Recognizing a cardiovascular emergency exists. Immediately call 911 to access the Emergency Medical System.
• Giving CPR promptly when needed. When CPR is performed correctly, mouth-to-mouth breathing and chest compressions help circulate blood (and oxygen) to vital organs. This buys time until defibrillation can be given.
• Administering early defibrillation. Defibrillation delivers a shock to the heart to stop the abnormal heart rhythm and allows a normal rhythm to resume. This is the single most important thing to save a life in someone with a cardiac arrest.
• Providing advanced life support. At this stage, licensed paramedics or other health care providers need to be on the scene with equipment for airway control, ventilation treatments, intravenous drugs and cardiac monitoring.

How AEDs work

If you've seen ER dramas on television, then you have a sense of how AEDs work. However, the shocks produced by automated external defibrillators are much smaller than the ones emitted during hospital defibrillation, so AEDs pose little risk to either the victim or the person using the equipment.

Although AEDs are miracles of modern medical machinery, they can be easily operated and do not take much training to use.

In teaching people how to use an AED, the American Heart Association keeps things simple. For example, rather than encouraging untrained rescuers to check for a pulse, the organization instructs them to simply check for signs of life or circulation.

AEDs provide voice-prompted messages that guide the user through the complete operating sequence. To use the device, you peel off the adhesive stickers from the backs of two electrodes and place them on the bare skin of a victim's chest with one electrode over the heart and another slightly to the left. You turn on the machine, and it does an analysis of the victim's heart rhythm. It delivers a shock only if it diagnoses a problem. AHA recommends that the moment you press the SHOCK button, you must make sure that no one, including yourself (the AED operator), touches any part of the victim.

Some of the "smart" AEDs even talk people through CPR if the rhythm is not one that is recognized as shockable. CPR can also be important in cases of cardiac arrest. While AEDs get the heart beating again, CPR, if needed, keeps the blood flowing to keep the brain and heart alive until an emergency medical crew arrives. Don't do CPR while the machine is giving a shock. Remember that patients who are breathing on their own do not need CPR.

Both the American Heart Association and the American Red Cross offer CPR and AED courses. The heart association's "Heartsaver AED program" includes training in both CPR and AED use and can be completed in three to four hours. To find out more about Heartsaver AED, call 1-877-AHA-4CPR (1-877-242-4277). If you want to get an AED in your workplace, you will need to have a doctor write an order for one.

Sources:

American Heart Association

American Red Cross

This article was reviewed and updated June 2007.