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AEDs: High-Tech Help for Heart Attacks

You've seen it time and again on television shows: After someone suffers sudden cardiac arrest doctors grab the paddles and deliver an electric shock to the patient to help restore a normal rhythm.

Such scenes may play out for real at airports, malls, sports arenas, health clubs, golf courses and even some businesses -- and you could be holding the paddles. That's because technology has given us the automated external defibrillator (AED), which is turning up far from hospitals. Many schools and public buildings already have AEDs.

Defibrillation is necessary when a heart begins to beat so fast that very little blood can be pumped out to the body. An AED uses an electric shock to help the heart return to its normal rhythm of contraction.

Here's a Q&A to bring you up to speed.

What is an automated external defibrillator?

An AED is an electronic device about the size of a large laptop computer. Trained emergency personnel -- or almost anyone else who has had some training -- can use an AED to see whether a cardiac arrest victim needs a jolt of electricity to the heart and, if so, to provide the right shock.

Do you need a lot of training?

No. The average person, with no medical background, can learn to use an AED. Usually, people learn to use an AED in a course that also teaches cardiopulmonary resuscitation (CPR). The computerized device will tell a rescuer to push the defibrillate button if the cardiac arrest stems from either ventricular fibrillation or ventricular tachycardia. Ventricular fibrillation is the most common heart-rhythm problem in victims of sudden cardiac arrest.

Won't the cost of devices such as AEDs keep them out of most community venues?

No. The cost of the device has fallen sharply in the past few years.

Do we really need AEDs in places other than hospitals?

The rate of sudden cardiac death can be reduced by placing AEDs in the community and by teaching people how to use them. Time is of the essence when cardiac arrest occurs. The rate of survival drops for every minute that goes by without this type of help.

Is an AED useful for all types of cardiac arrest?

No. Other abnormal rhythms, such as a very slow heart rate or no heart beat at all, cannot be treated with an AED. When a user puts the AED's electrodes on a victim's chest, the device will read whether the patient's heart needs to be shocked or not. Then the AED will prompt the rescuer through visual and voice commands about the next step. Many of the newer models will talk you through it and will deliver the shock itself if it reads a shockable rhythm.

Do AEDs make CPR obsolete?

Absolutely not. The two go hand in hand. An AED can restore a normal heart rhythm in certain cases; chest compressions in CPR are used to help keep blood flowing through the heart and the body. CPR can double the chances of survival when used at the moment of collapse and just before an AED delivers a shock. CPR should be started while someone runs for the AED.

Does research back the community use of AEDs?

Yes. Research shows the survival rates of people who had sudden cardiac arrest in casinos and got prompt AED treatment from security personnel trained to use AEDs. The survival rate for people who got their first shock no more than three minutes after collapse was close to three-fourths, compared with about one-half for those shocked after more than three minutes.