The Chain of Survival Revisited:
The Emergence of Early Recognition
as the Unsung Vital Link

Mary Newman

It is a fundamental tenet of emergency cardiac care (ECC) that we best serve people who experience sudden heart problems through an integrated systems approach to patient care. In other words, it takes teamwork to save a life. - This theme has been constant throughout the brief history of ECC. As early as 1968, Peter Safar, MD, called for a combination of BLS (airway control, breathing support and circulatory support) and ALS (restoration of spontaneous circulation) for victims of sudden cardiac arrest.¹

In 1974, the American Heart Association stated that emergency cardiac care includes 1) recognizing early warning signs of heart attacks, preventing complications, reassuring the victim and moving him to a life support unit without delay; 2) providing immediate BLS at the scene when needed; 3) providing ALS as quickly as possible; and 4) transferring the stabilized victim for continued cardiac care."² In 1986, the AHA formally recognized the need for a systems approach: "To be effective, ECC should be an integral part of a total community-wide emergency medical care system."³

Chain of Events

Within this context, the Chain of Survival - a simple public health message - was introduced. By the mid-1980s, the critical importance of rapid defibrillation for victims of sudden cardiac arrest was proven. As a result, there was a growing controversy about what bystanders should do first if they encountered an adult who had suddenly collapsed and was unresponsive. Conventional wisdom said to start CPR. Ken Stults, then of the University of Iowa, argued instead that the public should be taught to "phone first."⁴ His rationale: the quickest way to get the defibrillator to the patient's side was to reach for a phone.

Inspired by the wisdom of the phone-first message, the Chain Of Survival concept was designed to continue the emphasis on citizen CPR, while conveying the message about the urgent need to summon the defibrillator. The earliest version of the Chain of Survival consisted of three primary links that symbolized early EMS access, early CPR and early defibrillation (see Figure 1). At the left end of the Chain was a partial link, symbolizing early recognition. At the right end was a partial link symbolizing early ALS. These links were left open to suggest that emergency cardiac care comprises a continuum with variable end points difficult to define. ^5,6

In 1987, the Chain of Survival metaphor was used for the first time in the Citizen CPR Foundation's promotional brochure for its annual conference . Working to strengthen the Chain of Survival" soon was a slogan for the foundation. One of the first to recognize the Chain as a valuable educational tool was Richard Cummins, MD, who incorporated the idea into his '88 conference talk on early defibrillation. Cummins modified the Chain to include four links: early access, early CPR, early defibrillation and early advanced care. Later, Cummins and Stults brought the concept to the AHA. Cummins; Joseph Ornato, MD; William Thies, PhD; Paul Pepe, MD; and others wrote a landmark paper on the subject⁷ that the AHA soon adopted and promoted.⁸"

Figure 1: Three primary links connected the first Chain of Survival, published in JEMS in 1989.
Figure 2: The Chain of Survival icons created for the premiere issue of Currents in Emergency Care,1990.
Figure 3: The version used by the AHA was introduced in 1991.
Figure 4: The Chain of Survival advocated by the Early Heart Attack Care program.

FIGURE 1

FIGURE 2

FIGURE 3

FIGURE 4

The Strongest Link

Thus, the Chain of Survival gained momentum. Today, it's a widely recognized concept adopted by numerous health care organizations worldwide. But a decade after the Chain's introduction, the time has come for greater emphasis on the original first link: early recognition.

While the Chain of Survival was originally conceived purely as an action plan for responding to victims of sudden cardiac arrest (i.e., people who were clinically dead), early recognition broadens that perspective. The early recognition link teaches the public to recognize when someone has collapsed and does not respond-and to obtain help immediately.

The Chain of Survival may also be viewed as an action plan for responding to all victims of sudden cardiac emergencies-including victims of acute coronary events (those still alive but at high risk of sudden cardiac arrest). In this case, the recognition link teaches the public that it is critically important to recognize the early warning signs of a heart attack before it progresses to sudden cardiac arrest.⁹ In other words, one of the most important functions of the recognition link is to teach the public to intercept the medical emergency when it is most manageable and there is the greatest chance for success.

In either scenario, the recognition phase is pivotal. As Allan Braslow, PhD, and his colleagues have observed, the signals of emergencies are ambiguous, and bystanders overcome with feelings of anxiety and helplessness frequently fail to act quickly.¹⁰

Well-executed, a strong early recognition program can often render subsequent links unnecessary. Just as the prompt recognition of the screech of a smoke detector can eliminate the need to suppress a raging fire, so can early recognition of a heart attack, prevent the need for an all-out assault on cardiac arrest. If the heart attack is recognized in early stages, there may be no need for CPR, defibrillation or advanced care.

Raymond Bahr, MD, medical director of The Paul Dudley White Coronary Care System, St. Agnes Health Care, Baltimore, is a relentless advocate of the early recognition link. His Early Heart Attack Care (EHAC) program depicts early recognition as the preeminent link in the Chain of Survival¹² (see Figure 3). Bahr has concluded that heart attacks have beginnings. Because heart attack comprises the nation's number-one killer, early detection may be the single most important public health message today.¹³

Decoding Heart Hieroglyphics

The importance of recognizing a heart attack's warning signs, identified by Simon Dack, MD, half a century ago¹⁴ and long advocated by the AHA (and more recently by the National Heart Attack Alert Program),¹⁵ is more crucial now than ever in light of the availability of thrombolytic therapy. When heart attack patients receive thrombolytics within the first hour of symptoms, clots can be dissolved, heart muscle can be preserved and lives can be saved. According to NHAAP, only 3 to 11 percent of heart attack patients are treated within this golden hour, mainly because most patients wait two to six hours before seeking care.¹⁶

"If NHAAP is correct in asserting that 15,000 lives can be saved each year if all hospitals reduce time to thrombolytic therapy for acute myocardial infarction (AMI) patients to less than 30 minutes of arrival at the hospital, then intervening early when zero percent of such patients are having pre-infarction angina is even more important," says Bahr. "Recognition and intervention at this phase could save as many as 150,000 lives a year. It could enable us to take heart disease out of first place-the infamous position it has occupied since the turn of the century. This would be a major step forward in the war against heart attack deaths. It could well turn out to be the Rosetta Stone of the heart attack hieroglyphic problem."

For these reasons, Bahr called for a shift in the Chain of Survival paradigm to emphasize early recognition of symptoms that herald a cardiac emergency. This means educating the public about the classic signs of a heart attack: pressure; fullness; squeezing; pain in the center of the chest; pain lasting more than a few minutes; pain spreading to the shoulders, neck and arms; lightheadedness, fainting, sweating, nausea and shortness of breath.

This also means teaching the public about the "prodromal," or early signs of a heart attack that can appear 24 hours to three weeks before a heart attack occurs. These "soft" signs include mild, diffuse chest discomfort that doesn't feel like pain, comes and goes, increases with activity, subsides with rest, starts out mild and gets continuously stronger, and can be accompanied by fatigue, weakness, gastric discomfort and flu-like symptoms. According to Bahr, "The difference between chest pain and chest discomfort is like night and day." Recognizing vague chest discomfort before it becomes crushing pain can mean the difference between life and death.

Bahr takes his position a step further: "Crashing AMI and cardiac arrest cases should be perceived as system failures." This is a thoughtful position. Perhaps the Chain as currently perceived completely misses a huge subset of people whose lives may soon change radically because no one recognizes or reacts to their subtle -but serious--symptoms.

Surely, it's time to rethink the Chain of Survival and put more emphasis on the front end, where educational efforts to evoke mild behavioral change may yield the greatest results. Granted, studies have shown that present education initiatives don't affect behavioral change¹⁷ and have scant long-term effects.¹⁸ We have yet to understand why people who know the signs and symptoms still deny them and hesitate to act.

Though we may not know the best ways to present public health messages, we can refine the messages we ought to convey. With this in mind, there is something to be said for maintaining the Chain as a pure and simple educational model designed to address sudden cardiac arrest only. But thinking more broadly may have a more profound impact on public health.

Mary Newman, a longtime contributor to JEMS, is a founding member of the Citizen CPR Foundation and founding editor of the AHA/Citizen CPR Foundation publication, Currents in Emergency Cardiac Care. She created the Chain of Survival metaphor in 1987. She divides her time between Catalyst Research & Communications Inc., Carmel, Ind., and the Krannert Institute of Cardiology at Indiana University School of Medicine, Indianapolis. The views presented here are hers and do not necessarily reflect the views of the organizations with which she is affiliated.

Raymond Bahr, MD, MD, FACP, FACC, is medical director of the Paul Dudley White Coronary Care System, St. Agnes Health Care, Baltimore, Md. In 1981, Bahr established the Chest Pain Emergency Department (CPED), the first early cardiac care center in the world. Under his leadership, the CPED concept has evolved to include promotion of chest pain centers in conjunction with early heart attack care community education initiatives. More than 700 hospitals in the United States and abroad have adopted it.

References

1.	Safar P, Bircher N: Cardiopulmonary Cerebral Resuscitation, W.B. Saunders Company, Ltd., third edition, 1988.
2.	Moser R (ed), Gordon A (chairman): "Standards for cardiopulmonary resuscitation (CPR) and emergency cardiac care (ECC)." JAMA 1974, 227(7):838.
3.	Lundberg G (ed), Montgomery W (chairman): "Standards and guidelines for CPR and ECC." JAMA, 1986, 255(21):2910.
4.	Stults, K: "Phone First!: Making Rapid Defibrillation Programs More Rapid", Jems, September 1987, 12(9): 28.
5.	Newman M: "Chain of Survival Concept Takes Hold" JEMS, August 1989, 14(8):11-13.
6.	Newman M: "The Chain of Survival: converting a nation." Currents in Emergency Cardiac Care, 1990, 1(1):3.
7.	Cummins R, Ornato J, Theis W, Pepe P, et al: "Improving survival from sudden cardiac arrest: the "Chain of Survival concept." Circulation, 1991 83:1832-1847.
8.	Lundberg G (ed), Kerber R (chairman): "Guidelines for CPR and ECC: recommendations of the 1992 national conference." JAMA, 1992, 268:2172-2183.
9.	Half of all cases of sudden cardiac arrest are preceded by heart attacks. See Master AM, Dack S, Jaffe HL: "Premonitory symptoms of acute coronary occlusion; a study of 260 cases." Annals of Internal Medicine, 1941, 14:1155.
10.	Perez C, Braslow A, Bock H: National Standard Curriculum for Bystander Care. U.S. DOT NHTSA, 1992.
11.	Of course, if heart attacks can be prevented altogether through healthy lifestyles, that's even better, but that is a subject for another article.
12.	For information on the EHAC program, contact St Agnes Health Care, 900 Caton Ave., Baltimore, MD 21229; 410/368-3200; http://www.EHAC.org.
13.	Bahr R, McIntosh H: "Reawakening awareness of the importance of prodromal symptoms in the shifting paradigm to early heart attack care (EHAC)." Clinician 1996, 14(4).
14.	Master AM, Dack S, Jaffe HL: "Premonitory symptoms of acute coronary occlusions study of 260 cases." Annals of Internal Medicine, 1941, 14:1155.
15.	For information on the National Heart Attack Alert Program, contact the NHLBI Information Center, PO Box 30105, Bethesda, MD 20824-0105, 301/251-1222, fax: 301/251-1223.
16.	Heart Memo, Fall 1997, National Institutes of Health.
17.	Ho MT: "Delay between onset of pain and seeking medical care: effect of public education." Ann Emerg Med, 1989, (18): 727-731.
18.	Herlitz J, et al: "Follow-up of a one-year media campaign on delay time and ambulance use in suspected AMI." European Heart Journal, 1992, 13:171-177; Braunwald E. Acute myocardial infarction "the value of being prepared. (Editorial) New England Journal of Medicine 1996;334(1):51-52.
19.	Braunwauld E: "Acute Myocardial Infarction-the value of being prepared." New England Journal of Medicine, 1996, 334(1) 51-52.