What Is the Chain of Survival?

One worker calls for help while another retrieves a closed AED case from a wall cabinet.

The Chain of Survival is a series of actions that, done quickly and in order, give a person in cardiac arrest the best chance to live. Each link depends on the one before it.

The 2025 American Heart Association (AHA) Guidelines use one Chain of Survival with six links. The first three belong to the people who are there when someone collapses, which is why our classes focus on them.

What are the six links in the Chain of Survival?

The 2025 AHA Guidelines name six links. In class, we use shorter labels for the same links:

Recognition and activation (Call 911)
High-quality CPR (CPR)
Defibrillation (AED)
Advanced resuscitation (EMS care)
Post-cardiac arrest care (Hospital care)
Recovery and survivorship (Recovery)

The 2025 Guidelines use this single chain for every cardiac arrest: adult or child, in a hospital or out of one.

Why do the first three links belong to bystanders?

Because cardiac arrest usually happens far from a hospital. About 350,000 people in the U.S. have a cardiac arrest outside a hospital each year, and about 90% do not survive. About 71% of adult cardiac arrests outside a hospital happen at home.

Help takes time to arrive. One study found a median EMS response of about 7 minutes nationally and about 13 minutes in rural areas. The minutes before that are yours.

In 2024, only about 42% of people who had a cardiac arrest outside a hospital received bystander CPR, and only about 13% had a bystander use an AED. Those are the links most often left empty.

In our classes, we sum up those first three links as Activate EMS, Start CPR, and Defibrillate with an AED. Those are the same three links.

What does each bystander link look like?

Call 911. Recognize the emergency: the person is unresponsive and not breathing normally, or only gasping. Point at someone and tell them to call 911 and get the AED. See What to Do First in a Medical Emergency.

CPR. Push hard and fast in the center of the chest. CPR keeps blood moving until the AED and EMS arrive. Our guide on how to do CPR covers adults, children, and infants.

AED. Use it as soon as it arrives. It only shocks if a shock is needed. See how to use an AED.

What happens in the last three links?

EMS crews take over with advanced care. The hospital team then provides care after the cardiac arrest.

The final link, recovery, continues long after the person goes home. In 2024, about 10.5% of people who had a cardiac arrest outside a hospital survived to leave the hospital.

The Chain of Survival is not the same everywhere

The idea of a Chain of Survival is shared across the field, but organizations draw it differently. The American Red Cross and the European Resuscitation Council each teach their own version, and the number and names of the links differ.

The American Red Cross, for example, added a recovery step to its cardiac arrest chains of survival in 2021.

If you took a class somewhere else and remember a different number of links, you did not learn it wrong. Our class uses the six links from the 2025 AHA Guidelines. The core message is the same: act fast, call for help, start CPR, and use an AED.

This article is general education. It does not replace hands-on CPR and first aid training, where you practice these skills with an instructor.

How LP Health Directions can help

CPR and First Aid classes in Phoenix and Tucson, where you practice the first three links hands-on.
On-site Group Training for daycares, schools, churches, and workplaces.
AED Solutions for AED sales, leasing, and management.
Ready to train? Book a class or contact us.

Sources

Reviewed September 28, 2026. This article provides general education and does not replace first aid and CPR training, medical advice, or 911 guidance.

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