The Cardiac Chain of Survival is a popular metaphor used to outline the steps required to save a life in a cardiac emergency. Follow the chain of survival, and maximize a patient’s odds of recovery.
The idea was formally introduced in 1989 in the Journal of Emergency Medical Services (“The Chain of Survival Takes Hold,” JEMS 1989;14:11-13). Over the years, it has been adapted, expanded, amended, and ultimately adopted by the American Heart Association for the purpose of educating lay responders.
The AHA’s most current out-of-hospital Cardiac Chain of Survival is divided into five links:
1. Recognition of Cardiac Arrest & Activation of the Emergency Response System
“Recognizing cardiac arrest” and “calling 9-1-1” are sometimes listed as two separate links in the chain of survival, but the American Heart Association combines them into a single step.
Recognizing cardiac arrest can be tricky, as some people confuse it with other cardiovascular episodes. A person experiencing cardiac arrest:
- May show signs of chest pain or tightness shortly before the episode
- Will lose consciousness and collapse, usually without warning
- Will not be breathing
- Will not have a pulse
- Will not have a heartbeat
- May exhibit agonal breathing (in about 40% of cases)
This should not be confused with a heart attack, in which a person suffers and possibly collapses but continues breathing. For more information, refer to our guide to cardiac arrest vs. heart attack.
If you recognize someone going into cardiac arrest, call for emergency services immediately.
2. Early CPR With an Emphasis on Chest Compressions
When cardiac arrest occurs, the heart is no longer able to deliver oxygen-rich blood to the brain and other vital organs. Without constant blood flow, these organs start to degrade. Death can occur within minutes.
The purpose of cardiopulmonary resuscitation (CPR) is to help restore the movement of blood to these organs until the heart resumes function. It’s a stopgap measure to slow the decay of the internal organs while you wait for help to arrive.
Traditional CPR requires alternating between chest compressions and rescue breaths—deliver 30 compressions followed by 2 breaths, and then repeat until help arrives. However, the AHA recommends[mfn]uchealth.org[/mfn] that untrained lay responders focus on compression-only CPR. So if you have not received CPR training, skip the rescue breaths and just perform chest compressions as follows:
- Roll the patient onto their back and expose their bare chest as you kneel beside them.
- Place both hands flat against the center of the patient’s chest and push down in even, repetitive movements:
- Maintain a pace of 100 to 120 beats per minute—you can follow the beat of the Bee Gees’ Stayin’ Alive.
- Push down at a depth of 2 to 2.4 inches (5 to 6 centimeters).
- Allow the chest to rise fully between compressions.
3. Rapid Defibrillation
CPR alone can double or triple a patient’s odds of survival, but CPR combined with rapid defibrillation can increase the patient’s survival rate to as high as 75%[mfn]ncbi.nlm.nih.gov[/mfn]. This number is monumental when you consider that the average survival rate for out-of-hospital cardiac arrest is only around 10%[mfn]cpr.heart.org[/mfn]. This is why it’s so important for every office, hotel, school, church, gym, and public gathering place to have AEDs available.
If you do not have an automated external defibrillator (AED) handy, just continue CPR until help arrives. However, if you do have an AED, retrieve it immediately and start the defibrillation process.
If multiple people are available at the scene, one person should begin CPR while someone else calls 9-1-1 and retrieves the AED. As soon as the AED is available:
- Turn on the device. This is done by lifting the lid or pressing a “Power” button.
- Follow the voice and/or visual instructions provided by the AED.
- Attach the electrode pads to the patient’s bare chest. Use the diagram on the back of each pad as a placement guide.
- Press the “Shock” button onlyif prompted to do so by the AED’s voice coach.
- Stand clear while the AED delivers its shock. Ensure that nobody is touching the patient.
If the AED fails to find a shockable rhythm, or if the shocks are unsuccessful in reviving the victim, continue CPR until help arrives.
4. Basic and Advanced Emergency Medical Services
The final two links in the Cardiac Chain of Survival are intended for emergency services personnel. When medics arrive, they will assess the patient on the scene and administer additional medical services. These services may include additional CPR and defibrillation with a professional-grade defibrillator.
If you were able to use an AED, notify the emergency services professionals immediately. Many AEDs will record heart analysis and treatment data onto an internal hard drive. This data may be stored on a memory card, or it may be transferable to a computer via USB or Wi-Fi. By downloading this information, EMS professionals can learn more about the patient’s condition and customize their treatment accordingly.
5. Advanced Life Support and Post-Cardiac-Arrest Care
After assessing and treating the patient at the scene, EMS professionals will transport the individual to a medical facility for additional treatment and monitoring. If the patient makes it to this stage, it’s assumed that they have been revived—as an individual will only survive for a few minutes under cardiac arrest.
While in the hospital, the patient will receive ongoing supervision from a team of medical professionals. Doctors may administer drugs like adrenaline, lidocaine, and amiodarone to address any heart arrhythmias and help reduce the odds of a recurrent cardiac arrest.
Doctors will also run tests to determine what caused the condition. Depending on their findings, they might recommend a corrective procedure like a coronary artery bypass grafting or angioplasty. In some cases, they might recommend the installation of an implantable cardioverter defibrillator (ICD), which uses mild electrical shocks to manage heart arrhythmias in real time.
All clinical procedures will be carried out with the goal of healing the patient and reducing the chance of a future cardiac emergency.
How to Support the Cardiac Chain of Survival
You never know when a cardiac emergency will strike, but you can be prepared for the unexpected:
- Consider taking a CPR certification course. If you’re able to confidently perform chest compressions and rescue breaths in an emergency, you’ll be more prepared than a majority of bystanders.
- Invest in an AED for your home, business, or facility. When comparing AEDs for sale, be sure to choose from among trusted, FDA-approved brands like ZOLL, Philips, Defibtech, and Cardiac Science.
If you’re prepared, the rest is easy. Just call 9-1-1, start performing CPR, and use the defibrillator. Emergency services will take care of the rest. The Cardiac Chain of Survival is all about giving the patient the best opportunity for a successful recovery. By simply following the guidelines set by the American Heart Association, you could be the one who saves a life.
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