AEDs: High-Tech Help for Cardiac Arrest

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

Technology has given us the automated external defibrillator (AED), which can be found in schools and public buildings, airports, malls, sports arenas, health clubs, golf courses, and some businesses.

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.

Here are some FAQs to help 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 undergone training — can attach an AED to a cardiac arrest victim, who may need a jolt of electricity to the heart.

Do you need training to use an AED?

No. Most anyone with a medical background can learn to use an AED. Usually, people learn to use an AED in a course that also teaches CPR. The computerized device will tell a rescuer to push the defibrillate button if the cardiac arrest is from an abnormal heartbeat that could respond to a shock. (Not all rhythms will.) This could be 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 like AEDs keep them out of most places?

No. The cost of AEDs has decreased a lot in the past few years.

Are AEDs really needed 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. Seconds and minutes count 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 like a very slow heart rate or no heartbeat at all, cannot be treated with an AED. When a user puts the AED's electrodes on a victim's chest, the device determines whether the patient's heart needs to be shocked or not. Then the AED will instruct the rescuer about the next steps. Many of the newer models talk the rescuer through the steps. They automatically deliver the shock if appropriate.

Do AEDs mean CPR is no longer needed?

Absolutely not. The 2 go together. 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 right when a person collapses and just before an AED delivers a shock. CPR should be started while someone else gets the AED.

Does research back the community use of AEDs?

Yes. One study looked at the survival rates of people who had sudden cardiac arrest in casinos and got AED treatment from security personnel. There was a 75% survival rate for people who got their first shock within 3 minutes compared to a 50% survival rate for those shocked after more than 3 minutes.