The “Chain of Survival” refers to the chain of events that must occur in rapid succession to maximize the chances of survival from sudden cardiac arrest (SCA). The metaphor is a simple way to educate the public about its vital role in helping SCA victims. It suggests that each link is critical and interdependent, and the Chain of Survival is only as strong as its weakest link. Bystanders can help save lives by addressing the first four links in the Chain of Survival.

A strong Chain of Survival can improve chances of survival and recovery for victims of cardiac arrest.

You don't need to be a trained medical professional to help save a life. As a layperson, having an awareness of SCA and knowing how to respond can make all the difference between life and death. If a layperson witnesses sudden cardiac arrest, they should follow these six links of the Chain of Survival:

• Activation of the emergency response system
• Immediate high-quality CPR
• Rapid defibrillation
• Basic and advanced emergency medical services
• Advanced life support and post-arrest care
• Recovery
• SCA survivors should have formal post-event assessments and receive support for their physical, cognitive, and psychosocial needs.
• Survivors and their caregivers need comprehensive discharge planning, including treatment recommendations that support a survivor's return to activities and social/role functioning.

Beyond the Links

For the best chance of surviving an out-of-hospital cardiac arrest, victims should receive CPR and early defibrillation within 3 to 4 minutes of the cardiac arrest, followed by advanced life support within the first 8 minutes of the arrest.

AHA recommendations:

• All communities should adopt the principle of early defibrillation.
• All personnel who are expected to perform basic CPR as part of their professional duties should be equipped with an AED and be trained to operate it.
• Health and emergency professionals who have a duty to respond to a person in cardiac arrest should have a defibrillator available immediately, or within 1 to 2 minutes at most.

Common questions about the Chain of Survival

The Chain of Survival is designed to be as accessible as possible. However, rescuers may have a few questions before they feel comfortable following it. Here are some answers to frequently asked questions regarding this process.

When should you begin the Chain of Survival?

The Chain of Survival should be enacted immediately following a reasonable suspicion of sudden cardiac arrest, with bystanders calling emergency services or in-hospital personnel diagnosing the problem. If no pulse is found, then victims must receive CPR and rapid defibrillation within 3 to 4 minutes of cardiac arrest.

What is the Pediatric Chain of Survival?

The Pediatric Chain of Survival outlines the recommended process for helping a child or infant through sudden cardiac arrest. This follows the same general guidelines as the regular Chain of Survival, with a few exceptions: The first link encompasses prevention and early recognition, and the requirements for CPR and defibrillation are adjusted to match the heart rate of a child in his or her age range.

What is rapid defibrillation and why is it important?

Defibrillation is the application of electric shock to an individual’s heart to help it beat at a regular rhythm. Rapid defibrillation puts emphasis on quickly using a defibrillator to aid an SCA victim, as doing so helps increase the victim’s chance of survival.