In order for a victim of sudden cardiac arrest (SCA) to have the best chance at being revived and recovering, a number of things have to happen. This is known as the “Cardiac Chain of Survival.”

First in the Cardiac Chain of Survival, there needs to rapid recognition that the person needs emergency help. So, recognizing the signs of life (such as consciousness, normal breathing, body movement and a pulse) is critical. If there are no obvious signs of life, then calling 911 (or your local emergency number) is the correct thing to do.

Next, if you find no obvious signs of life, you need to begin CPR. The earlier you begin compressions, the better, to give the victim the best chance of survival. Whether it’s “hands-only CPR” or “high-quality CPR,” you cannot delay in initiating care.

Next, because CPR all by itself rarely is enough to revive a person in SCA, an automated external defibrillator (AED) must be used. And, since a person’s chance of survival drops about 7-10% every minute it’s delayed, it’s critical that someone find one right away.

Finally, in most cases, you’re going to need more advanced care from paramedics and/or EMTs, to help restart the victim’s heart. Like all of the other links in the Cardiac Chain of Survival, this link is critical. But more advanced providers are not going to magically appear, unless someone has recognized the emergency and activated the emergency medical services (EMS) system by calling 911.

What If You’re Alone?

If there are at least two people to help, one person can begin care, while the other person goes to call 911 and bring back an AED. But what if you’re alone, and there’s no one else within shouting distance to do those things for you, you have to ask yourself, which is more important, beginning care or making the 911 call and getting a defibrillator? And the answer is — it depends!

This is where it gets complicated. If you have reason to believe that the problem is cardiac in nature, then you need more advanced care and an AED on the way as fast as possible. However, if you have reason to believe that the problem is respiratory in nature, then providing care first is more important.

Here are some general guidelines to help you make that determination. If the victim is an “adult” (meaning age 12 or older, or the beginning of puberty) and is unconscious for unknown reasons, then you want to provide care first. If the victim is under that age and is unconscious for unknown reasons, then you want to make the phone call and get the AED first.

And here’s where it gets even more complicated, as there are exceptions to the above policy. In the case of an adult who you know is suffering from a respiratory emergency (as in witnessed choking, drowning, etc.), then you would give care first. And in the case of a child or infant who you know has a history of heart problems, then you would want to make the phone call and get the AED first, before providing care.

While this sounds confusing (and, unfortunately, it is), in most circumstances, there is someone within shouting distance. Tell them to “call 911 and bring back an AED,” while you begin caring for the victim.

Video Demonstration

Here’s a video from the American Red Cross that demonstrates the links in the Cardiac Chain of Survival very well:

Cardiac Chain of Survival