CPR vs. AED: Understanding the Lifesaving Differences

Cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) training are two different life-saving techniques that, when used together, are the most effective way of saving a victim of sudden cardiac arrest. Generally, these two techniques are taught together in first aid courses, but if you are unsure of the difference between the two or when to use each method, keep reading.

What is CPR?

CPR refers to the first aid technique where an individual repeatedly compresses a person’s chest to stimulate blood flow and essentially provides an artificial heartbeat. This method is used for someone who has experienced sudden cardiac arrest, which is when a person’s heart unexpectedly stops beating. This procedure will help prevent the patient’s organs from dying, and the chances of brain damage before their heart can be restarted.

What does AED mean?

Chances are you’ve seen an AED before, although it was likely on a medical TV show. You may remember a familiar scene where the doctor grabs a device, pull out two paddles, place them on the patient’s chest, and yells “CLEAR!” before shocking the patient with the two paddles. The device that the doctors are using in that scenario is an AED, a portable device that provides electric shocks which can be used to restart the heart. CPR alone is very unlikely to restart a heart, but when CPR is used with AED, a person’s chance of survival significantly increases.

AEDs are very well designed and will automatically analyze if the heart has regular heart rhythm or abnormal heart rhythm. It will only give a shock if the victim is in ventricular fibrillation (VF) or ventricular tachycardia (VT). In addition, they will not shock patients who don’t need it, so you don’t have to worry about accidentally shocking yourself when using one. This simple design means that even those with little to no experience can effectively use AEDs to save someone’s life. Check out this essential guide to CPR and First Aid.


How does an AED work?

When a person is in VF or VT, the nerve impulses being sent from the brain to the heart are so confusing that the heart cannot work properly and usually flutters or twitches instead of beating. An AED will shock the heart to stop it from spasming. The hope is that the nerve impulses will “re-set” and resume their normal pattern so that the heart can begin beating normally again.

Where can I find an AED?

AEDs are common in public locations, including major department stores, shopping centers, airports, grocery stores, and public transit vehicles. Your workplace likely has one too, and you may want to consider buying one for your home if your family has a history of heart disease. However, your first step in a medical emergency should always be to call 911, and 911 operators can usually tell you where the closest AED is. First responders will always have one, so if you are without an AED, just do CPR until help arrives. Hopefully, we’ll soon have better ways to find AEDs, as there are many companies creating apps to locate all the AEDs around your location during an emergency.

How do I use an AED?

Before using the AED, make sure the patient is not lying in any puddles of water. If they are, move them to a drier area. Once they are in a safe location, turn on the AED. It will give you step-by-step instructions on what to do (or there should be written instructions with the AED). Essentially, you will need to expose the person’s chest, make sure it is dry, and trim any excess chest hair. Having too much hair will prevent the electrodes’ sticky pads from having a good connection with the person’s skin. Once you have done that, you can place the electrode pads on the person’s chest- one pad on the right-center of the person’s chest above the nipple and the other slightly below the other nipple and to the left of the ribcage. You may want to remove any metal objects like jewelry and underwire bras from the person, to prevent burns when the device shocks them.

The device will analyze the patient’s heart and let you know if an electric shock is needed. Then, stand back and press the “shock” button on the AED to deliver a shock. Although don’t worry, if you happen to be touching the patient when the electrical shock occurs, you’ll likely only feel a slight tingle.

And don’t worry about getting sued for using this procedure on a stranger- Good Samaritan laws will protect you.

CPR vs AED: How to Decide What to Use?

If you are with a person who has experienced sudden cardiac arrest, your first step should always be to call 911. If you’re unable to leave the victim, ask someone else to call 911 on your behalf. Whether you should do CPR or get an AED will depend on your situation.

If you have another person with you, one of you should go find an AED while the other does CPR. However, if you are alone, you may be better off just doing CPR if you don’t know where an AED is or if there isn’t one nearby. If you are unsure of what to do, ask the 911 operator, and they should be able to direct you on the best steps to take.

Also Read- CPR Training vs. AED Training – Which One Do I Need?

Frequently Asked Questions About CPR and AED

How do I know the person is in cardiac arrest?
A cardiac arrest victim doesn’t show any signs of breathing or movement. There are some cases where the color around the lips and eyes will turn blue.

What is Ventricular Fibrillation?
Ventricular fibrillation is a dangerous type of arrhythmia or abnormal heartbeat. It affects the heart’s ventricles.

Should I Leave the Pads On If No Shock is Advised?
Yes. Whether a shock has been successfully delivered or if the AED says”no shock advised,” you should always leave the pads on. The victim may go into Ventricular Fibrillation a second time, or the device may recognize a shockable rhythm. Always leave the device on until emergency medical personnel have taken over.

Can You Get CPR AED Certified Online?

Get CPR Certified in Minutes for as low as $19.95

Join thousands of professionals that have been certified online with us
100% Online Certification
Fast & Convenient
Instant Certification Card
Nationally Accepted
Get Started
5 star
from 259,205 reviews


Tailored for the community and workplace
Offer Expires:
Comprehensive CPR Training Across All Ages
Choking response training
Recovery position technique course