History of CPR

Cardiopulmonary resuscitation is an important life saving first aid skill, practised throughout the world. It is the only known effective method of keeping someone who has suffered cardiac arrest alive long enough for definitive treatment to be delivered (usually defibrillation and intravenous cardiac drugs). In 1954, James Elam was the first to demonstrate experimentally that cardiopulmonary resuscitation (CPR) was a sound technique, and together with Dr. Peter Safar he demonstrated its superiority to previous methods. Peter Safar wrote the book ABC of resuscitation in 1957. In the U.S., it was first promoted as a technique for the public to learn in the 1970s

There were some techniques to keep people alive developed in the 18th century, but it was well in to the 20th century before Elam and Safar discovered and published the truly effective method known as CPR. Safar conducted research on existing basic life support procedures including controlling a person’s breathing airway by tilting back his or her head with an open mouth; and using mouth-to-mouth breathing. He combined these with a procedure known as closed-chest cardiac massage to become the basic life support method of CPR.

Throughout his life Safar was hesitant to take credit for “inventing” CPR. The way he saw it, he merely brought to light effective procedures that humans had already discovered, putting them together into what he called “the ABCs”—maintaining a patient's Airway, Breathing and Circulation. He worked hard to popularize the procedure around the world and collaborated with Norwegian toy maker Åsmund Laerdal to create “Resusci Anne,” the CPR training mannequin. Laerdal now is a medical equipment manufacturer.

Safar also created the first guidelines for community-wide emergency medical services, or EMS; he founded the International Resuscitation Research Center (IRRC) at the University of Pittsburgh, which he directed until 1994; and he was nominated three times for the Nobel Prize in medicine.

First attempts at resuscitation in the 18th Century
The Enlightenment, starting around 1750, was a remarkable time in human history; a time of scientific discovery, political democracy, and a growing belief that humans could unravel the mysteries of the universe. All scientific principles were challenged and explored, including the mystery of death itself, and whether it could be reversed, postponed or even stopped altogether. In this climate, it was inevitable that the concept of resuscitation would become the focus of study and work by interested scientists of the age.

The first city to teach and promote resuscitation was Amsterdam, located in the heart of the European Enlightenment and also a city of canals—therefore a city with many drownings – as many as 400 per year. Death from cardiac disease was still not prevalent and sudden deaths were mostly from accidents.

In August 1767 a few wealthy and civic-minded citizens in Amsterdam gathered to form the Society for Recovery of Drowned Persons&lt;ref&gt;Johnson A, An account of some societies at Amsterdam and Hamburg for the recovery of drowned persons, 1773, London, pg. 119.&lt;/ref&gt;. This society was the first organised effort to respond to sudden death.

Within 4 years of its founding, the society in Amsterdam claimed that 150 persons were saved by their recommendations&lt;ref&gt;Royal Humane Society, Annual Reports, 1787, 1788, 1789. London&lt;/ref&gt;. Their techniques involved a range of methods to stimulate the body. The members of the society recommended&lt;ref&gt;Cary RJ, A brief history of the methods of resuscitation of the apparently drowned. Journal of Johns Hopkins Hospital Bulletin, 270 (1918):243-251.&lt;/ref&gt;:


 * 1) Warming the victim
 * 2) Removing swallowed or aspirated water by positioning the victim's head lower than feet
 * 3) Applying manual pressure to the abdomen
 * 4) Respirations in to the victim's mouth, either using a bellows or with a mouth-to-mouth method (mouth-to-mouth or mouth-to-nostril respiration is described including the advice that "a cloth or handkerchief may be used to render the operation less indelicate")
 * 5) Tickling the victim's throat
 * 6) 'Stimulating' the victim by such means as rectal and oral fumigation with tobacco smoke. This may seem very unusual in modern times, however it may have been that the nicotine was enough of a stimulant to engender a response in the “almost” dead
 * 7) Bloodletting

The first four of these techniques (or variations of them) are still in use today, whereas the last three are now out of line with modern medical thinking. However, regardless of the scientific merit of these techniques, it started a collective belief that resuscitation was possible, and the suddenly dead could be revived.

Following successes of this first society, rescue societies soon sprang up in most European capitals, all with the goal to find a way of successful resuscitating victims of sudden death. This theory proved so popular that Hamburg, Germany passed an ordinance in 1769 providing notices to be read in churches describing assistance for drowned, strangled, and frozen persons and those overcome by noxious gases, probably the first example of mass medical training. The Royal Humane Society in London (no connection to the animal welfare organization in the United States), founded in 1774, served as the model for societies in New York, Philadelphia, and Boston. These rescue societies of the 18th century were the precursors of today’s emergency medical services.

For the next 150 years, scientists (not to mention quite a few quacks) advocated literally hundreds of resuscitation techniques. Some were even partly effective especially for respiratory emergencies. For example, the back pressure-arm lift method (“out goes the bad air, in goes the good air”) taught to countless thousands of Boy Scouts until the late 1950s could occasionally have saved a drowning victim&lt;ref&gt;Karpovich PV, Adventures in Artificial Respiration. Association Press, 1953, New York.&lt;/ref&gt;, as in drowning, the initial problem is a cessation of respirations and for the first 5–10 minutes the heart is still beating and if the victim can be extracted from the water and be induced to breathe the outcome may be good, but the technique was of no benefit for cardiac arrest as it did nothing for circulation, which it is now known, is the key factor to address in these victims.

Modern Resuscitation
Scientists and doctors started to try and address the problem from many different sides including developing new medications, devising new surgical techniques and identifying risk factors. Doctors James Elam, Peter Safar and Archer S. Gordon set to educating the world about rescue breathing, preventive measures and trying to discover a way to treat acute cardiac arrest.

Gordon initially did not support rescue breathing until he performed a study of his own using pediatric patients, reproducing Elam's results. Safar had also been working on the feasibility of rescue breathing, so they agreed that a concerted effort would be much more valuable than each working separately and possibly reproducing each others' work.

Prior to the 1950s, the accepted method of resuscitation was the chest-pressure and arm-lift technique that was shown to be ineffective by Safar and Elam. In 1954, Elam was the first to demonstrate experimentally that exhaled air ventilation was a sound technique. Elam and Safar (and later Gordon) performed many experiments demonstrating the superiority of the rescue breathing technique. The problem then became one of popularizing the method.

Organizations such as the American Red Cross provide training at local chapters in the proper administration of artificial respiration procedures. The Red Cross has been teaching this technique since the mid-1950s. For example, in Kalamazoo, Michigan, volunteer Roger Mehalek introduced a breathing trainer called Miss Sweet Breath 1959, a plaster and plastic training mannequin he created.

In New York, then State Health Commissioner, Herman Hilliboe was impressed with the technique. He commissioned Elam to write the instructional booklet titled "Rescue Breathing," which was distributed nationally in 1959. The success of the booklet spurred Elam to produce films demonstrating this new life-saving technique.

By 1960, rescue breathing had been adopted by the National Academy of Science, American Society of Anesthesiologists, Medical Society of the State of New York and the American Red Cross as the preferred method of resuscitation.

Several key discoveries and understandings were required to treat the problem, which would take decades to work out, and even now is not 'solved'. Doctors speak of the natural history of diseases as a way to understand how therapy alters the usual progression of a disease. For example, the natural history of breast cancer may be measured in months but treated with surgery or chemotherapy the disease can be measured in years or even cured. Sudden cardiac arrest is a disease with an extremely rapid natural history, measured in minutes, with an inexorable outcome. But when treated with CPR the course of death can be extended (CPR will delay the dying process) and if treated with timely defibrillation death can be aborted.

The modern elements of resuscitation for sudden cardiac arrest are cardiopulmonary resuscitation (CPR in turn consists of mouth-to-mouth ventilation and chest compression), defibrillation and emergency medical services (the means to bring these techniques to the patient quickly).

Mouth-to-mouth Ventilation
For a long time before it was formalised, it had been known by doctors and midwives that mouth to mouth resuscitation could be useful in bringing a lifeless newborn around. In 1946, during the middle of a Polio outbreak, an anesthesiologist, James Elam, applied this principle to an older child in an emergency situation&lt;ref&gt;Elam JO, Rediscovery of expired air methods for emergency ventilation, in Advances in Cardiopulmonary Resuscitation, Peter Safar, Ed, Springer Verlag, 1977, New York, pg 263-265.&lt;/ref&gt;. Elam described the event in his own words as "I was browsing around to get acquainted with the ward when along the corridor came a gurney racing - a nurse pulling it and two orderlies pushing it, and the kid on it was blue. I went into total reflex behaviour. I stepped out in the middle of the corridor, stopped the gurney, grabbed the sheet, wiped the copious mucous off his mouth and face, … sealed my lips around his nose and inflated his lungs. In four breaths he was pink"

On the evening before this rediscovery, Elam read a chapter on the history of resuscitation in which mouth-to-mouth ventilation for newborns was described. He credits this chapter for his “reflex behaviour.” Elam’s passion let to his proselytizing about the merits of mouth-to-nose ventilation. He set out to prove that exhaled air was adequate to oxygenate non-breathing persons. In 1951, Elam was on staff in the Department of Anesthesiology at Barnes Hospital in St. Louis, Missouri. As he was about to start his research into CO2 homeostasis, a new department chair was appointed who wanted all research in anesthesiology to be performed using animals, not humans. Elam realized this would not be feasible and moved to Buffalo's Roswell Park Memorial Institute along with his top two collaborators, Elwyn S. Brown, M.D., and Raymond H. Ten Pas, M.D. He obtained permission from his chief of surgery to do studies on postoperative patients before the ether anaesthesia wore off. In this study, he demonstrated that expired air blown into the endotracheal tube maintained normal oxygen saturation.

Several years later James Elam met Peter Safar, also an anesthesiologist, convincing him to join the effort to convince the world that expired air ventilation was effective. Safar set out on a series of experiments using paralysed individuals to show that the technique could maintain adequate oxygenation&lt;ref&gt;Safar P. History of cardiopulmonary-cerebral resuscitation, in Kay W and Bircher N, Cardiopulmonary Resuscitation, Churchhill Livingston, 1989, New York, pg 1-53.&lt;/ref&gt;. Peter Safar describes the experiments:

"Thirty-one physicians and medical students, and one nurse volunteered . . . Consent was very informed. All volunteers had to observe me ventilate anaesthetised and curarized patients without a tracheal tube. I sedated the volunteers and paralysed them for several hours each. Blood O2 and CO2 were analysed. I demonstrated the method to over 100 lay persons who were then asked to perform the method on the curarized volunteers."

These experiments provided compelling data to switch from manual to mouth-to-mouth ventilation. The United States military accepted and endorsed the method in 1957 and the American Medical Association followed suit in 1958 The May 17, 1958 issue of JAMA contains the following endorsement: "Skillful performance of expired air breathing is an easily learned, lifesaving procedure. It has revived many victims unresponsive to other methods and has been proved in real emergencies under field conditions. Information about expired air breathing should be disseminated as widely as possible".

Chest Compressions
Unlike cessation of respiration, an obvious sign of sudden death, the cessation of circulation, and particularly the rhythm of the heart, is not as easy to spot for a lay observer, although a trained eye now can see signs such as lack of perfusion. Perhaps as a result of this being less obvious, the appreciation of artificial circulation as a key factor in resuscitation lagged considerably behind the obvious need for artificial respirations.

If the scientists working on the problem appreciated the need to circulate blood, there was simply no effective means to do so. Even though closed chest massage was described in 1904, its benefit was not appreciated and anecdotal case reports did little to promote the benefit of closed chest massage. The prevailing belief was described in a physician’s quote from 1890, “We are powerless against paralysis of the circulation.”

The formalised system of chest compression was really an accidental discovery made by William Bennett Kouwenhoven, Guy Knickerbocker, and James Jude at Johns Hopkins University. They were studying defibrillation in dogs when they noticed that by forcefully applying the paddles to the chest of the dog, they could achieve a pulse in the femoral artery. Further meticulous experimentation involving dogs answered such basic questions as how fast to press, where to press, and how deep to press. This information gave them the belief that they were ready for human trials.

The first person saved with this technique was recalled by Jude: "She was rather an obese female who … went into cardiac arrest as a result of flurothane anesthetic. This woman had no blood pressure, no pulse, and ordinarily we would have opened up her chest. Instead, since we weren’t in the operating room, we applied external cardiac massage. Her blood pressure and pulse came back at once. We didn’t have to open her chest. They went ahead and did the operation on her, and she recovered completely."

In 1960 the three investigators reported their findings on 20 cases of in-hospital cardiac arrest in JAMA&lt;ref&gt;Kouwenhoven WB, Jude JR, Knickerbocker GG. Closed-chest cardiac massage, JAMA. 1960;173:94-97.&lt;/ref&gt;. Fourteen of the 20 patients (70%) survived and were discharged from the hospital. Many of the patients were in cardiac arrest as a result of anaesthesia. Three patients were documented to be in ventricular fibrillation. The duration of chest compression varied from less than 1 minute to 65 minutes. The JAMA article was very straightforward: chest compression buys time until the external defibrillator arrives on the scene. As the authors write in the article, "Anyone, anywhere, can now initiate cardiac resuscitative procedures. All that is needed is two hands". However, respiration received relatively little attention in the 1960 JAMA article. Many of the patients had been intubated and thus the need for mouth-to-mouth ventilation was not necessary. It was not long however, before this newly discovered technique was used in conjunction with the longer held techniques of artificial respiration.

The use of compression and ventilation together
The formal connection of chest compression with mouth-to-mouth ventilation to create CPR as it is practiced today occurred when Safar, Jude, and Kouwenhoven presented their findings at the annual Maryland Medical Society meeting on September 16, 1960 in Ocean City. In the opening remarks the moderator said, "Our purpose today is to bring to you, then, this new idea." It was so new that it was still without a name. The moderator stated that the two techniques "cannot be considered any longer as separate units, but as parts of a whole and complete approach to resuscitation". In his remarks Safar stressed the importance of combining ventilation and circulation. He presented convincing data that chest compression alone did not provide effective ventilation; mouth-to-mouth respiration had to be part of the equation.

To promote CPR, Jude, Knickerbocker, and Safar began a world speaking tour. In 1962 Gordon, along with David Adams, produced a 27-minute training film called "The Pulse of Life." The film was used in CPR classes and viewed by millions of students. For the film, Gordon and Adams devised the easy to remember mnemonic of A, B &amp; C standing for the sequence of steps in CPR, airway, breathing, circulation, which is still used today.

In 1963 cardiologist Leonard Scherlis started the American Heart Association's CPR Committee, and in the same year, the Heart Association formally endorsed CPR. In May 1966 the National Research Council of the National Academy of Sciences convened an ad hoc conference on cardiopulmonary resuscitation. The conference was the direct result of requests from the American National Red Cross and other agencies to establish standardized training and performance standards for CPR. Over 30 national organizations were represented at the conference. Recommendations from this conference were reported in JAMA in 1966&lt;ref&gt;Committee on CPR of the Division of Medical Sciences, National Academy of Sciences-National Research Council, Cardiopulmonary resuscitation, JAMA 1966;198:372-379 and 138-145.&lt;/ref&gt;.

Defibrillation
As early as the 1930s it was known that electric shocks, even small shocks, could induce ventricular fibrillation in dogs' hearts and more powerful shocks could reverse the fibrillation. This early research had been funded by the electric industry concerned about fatal accidents to linemen. Claude Beck, professor of surgery at Western Reserve University (later to become Case Western Reserve University) in Cleveland worked for years on a technique for defibrillation of the human heart. Beck believed that electricity could equally benefit the surgery patient whose heart fibrillated during surgery or induction of anaesthesia.

Beck probably witnessed his first cardiac arrest during his internship in 1922 while on the surgery service at the Johns Hopkins Hospital. During a urologic operation, the anaesthetist announced that the patient's heart had stopped. To the amazement of Beck, the surgical resident removed his gloves and went to a telephone in a corner of the room and called the fire department. Beck remained in total bewilderment as the fire department rescue squad rushed into the operating room 15 minutes later and applied oxygen-powered respirators to the patient's face. The patient died, but the episode left an indelible impression on him. Beck would go on to develop techniques to take back the management of cardiac arrest from the fire department and place it in the hands of surgeons.

Beck realized that ventricular fibrillation often occurred in hearts that were basically sound and he coined the phrase "Hearts too good to die." In 1947, Beck accomplished his first successful resuscitation of a 14-year-old boy using open chest massage and internal defibrillation with alternating current. The boy was being operated on for a severe congenital funnel chest. In all other respects the boy was normal. During the closure of the large incision in the chest, the pulse suddenly stopped and the blood pressure fell to zero. The boy was in cardiac arrest. Dr. Beck immediately reopened the chest and began manual heart massage. As he looked at and felt the heart, he realized that ventricular fibrillation was present. Massage was continued for 35 minutes at which time an electrocardiogram was taken that confirmed the presence of ventricular fibrillation. Another 10 minutes passed before the defibrillator was brought to the operating room. The first shock using electrode paddles placed directly on the sides of the heart was unsuccessful. Beck administered procaine amide, a medicine to stabilize the heart’s rhythm. Beck gave a second shock that wiped out the fibrillation. In a very few seconds a feeble, regular, and fast contraction of the heart occurred. The blood pressure rose from zero to 50 millimeters of mercury. Beck noted that the heartbeat remained regular and saw that the pressure slowly began to rise. Twenty minutes after the successful defibrillation, the chest wound was closed. By three hours, the blood pressure rose to a normal level, and the child awoke and was able to answer questions. The boy made a full recovery, with no neurological damage&lt;ref&gt;Beck CS, Pritchard WH, Feil HS. Ventricular fibrillation of long duration abolished by electric shock. JAMA, 1947;December 24;1230-1233.&lt;/ref&gt;.

Beck pioneered internal defibrillation of the heart. In other words the chest had to be open and the defibrillator paddles placed directly on the heart. It was ground breaking work but soon to be eclipsed by devices that could externally defibrillate the heart through the closed chest.

For Paul Zoll, well aware of Beck’s accomplishment, the development of an external defibrillator was a natural extension of his earlier work with an external cardiac pacemaker In 1955 a 67-year-old man survived several episodes of ventricular fibrillation, thanks to Zoll's external defibrillator, and went home from the hospital a month later. Over a period of four months, Zoll had successfully stopped ventricular fibrillation eleven times in four different patients. The energy required for defibrillation ranged from 240 to 720 volts. Zoll's findings were published in the New England Journal of Medicine in 1956.

The defibrillator designed by Zoll, as well as earlier versions invented by Kouwenhoven and Beck, utilized alternating current and were run from line current, the electricity from any wall socket. The decision to use alternating current rather than direct current was a practical one. Direct current batteries and capacitor technology both powerful enough to do the job and portable enough for practical use simply didn't exist in the early 1950s. These AC defibrillators were very large and heavy, primarily because they contained a transformer to step up the line current from 110 volts to 500 or 1000 volts. The only good feature is that they could be mounted on wheels and pushed down the hallway from one part of the hospital to another. Not many lives would be saved unless the inherent non-portability of AC defibrillators could be solved.

The portability problem was solved by Bernard Lown. Lown devised a defibrillator that utilized direct current instead of alternating current. A series of animal experiments on dogs in 1960 and 1961 and clinical uses in patients in the early 1960s established that DC shocks were extremely effective in shocking the heart&lt;ref&gt;Lown B, Cardioversion of arrhythmias Modern Concepts of Cardiovascular Diseases, American Heart Association 1964;33:863-868.&lt;/ref&gt;. What's more, it was clear that DC was actually safer than AC when applied through the chest wall. With direct current it was possible to use power, supplied by a battery, to charge a capacitor over a few seconds. The capacitor stored the energy until it was released in one massive jolt to the chest wall. The availability of new, small capacitors considerably reduced the size and weight of the device. - the defibrillator could now travel to the patient.

The first out of hospital defibrillation
For civilians, ambulance service for many years was merely a means to bring the patient to the hospital. In a few cities, interns rode ambulances as part of their training but provided no medical care at the scene. During the 1930s and 1940s municipal fire departments in some cities (including Los Angeles, Columbus, Baltimore, and Seattle) began to provide rescue, first aid, and resuscitation care. In 1966 the United States National Academy of Sciences and the President's Commission on Highway Safety issued reports decrying the unevenness of ambulance personnel competency and the lack of standard procedures. The commission described the carnage resulting from traffic accidents as the neglected disease of society. The subsequent National Highway Safety and Traffic Act of 1966 authorized the Department of Transportation to establish a national curriculum for prehospital personnel, which led to the training of emergency medical technicians (EMTs).

EMTs did much to upgrade the general performance of ambulance services throughout the United States. Their 80-hour course and certification, which included CPR, ensured that proper care would be provided to victims of motor vehicle accidents and other emergencies. Thus they could provide artificial ventilation and closed-chest massage at the scene and en route to the hospital.

However, EMTs were neither trained nor authorised to provide definitive care for cardiac arrest. They could not provide defibrillation; intravenous medications; or advanced airway control, such as endotracheal intubation. EMTs saved few, if any, victims of sudden cardiac arrest, largely because cardiac arrest occurred mostly in people's homes. The time required for EMTs to arrive and transport the patient to the closest emergency department was too long for resuscitation to be successful. Not even letter-perfect CPR can save a life if it takes too long for defibrillation and other advanced procedures to occur.

In 1965, Frank Pantridge turned his attention to this vexing problem of heart attacks and sudden cardiac death. His sensitivity to the problem came from two sources. First, personnel in the emergency department of the Royal Victoria Hospital in Belfast frequently commented on the number of patients coming in dead on arrival (DOA). Second, Pantridge had recently read a telling study in a medical journal that indicated that among middle-aged or younger men with acute myocardial infarction (MI), more that 60% died within 1 hour of the onset of symptoms. Thus the problem of death from acute MI had to be solved outside the hospital, not in the emergency room or the coronary care unit. "The majority of deaths from coronary attacks were occurring", he wrote, "outside the hospital, and nothing whatever was being done about them. It became very clear to me that a coronary care unit confined to the hospital would have a minimal impact on mortality." He wanted his coronary-care unit in the community.

Pantridge's solution was to develop the world's first mobile coronary-care unit, or MCCU. He staffed it with an ambulance driver, a physician, and a nurse. Pantridge encountered numerous obstacles to the creation of the MCCU. He dealt with them in his typical direct fashion, with determination to succeed and transparent contempt for politicians and any authority figure who opposed him. Even his cardiology colleagues were skeptical. "My noncardiological medical colleagues in the hospital were totally unconvinced and totally uncooperative," Pantridge said. "It was considered unorthodox, if not illegal, to send junior hospital personnel, doctors, and nurses outside the hospital." Pantridge's new program began service on January 1, 1966.

John Geddes was a resident in cardiology at the Royal Victoria Hospital in Belfast and worked on Pantridge's service. As junior member of the team it was Geddes' responsibility, which he shared with four other residents on the service, to ride on the newly christened ambulance when it was called into service.

Why did this breakthrough in cardiac care occur in Belfast, of all places? Geddes thought he knew the answer:

"I would say two reasons. One was Pantridge himself. He is a remarkable personality who is very persuasive. He can persuade people to do things, and . . . actually make them enjoy doing things that he has made them do because they are successful. So there was his tremendous enthusiasm behind the system. Then there was the fact that the layout of the [Royal Victoria] hospital was flat and it was quick and easy to get to people and resuscitate them. I didn't realize this at the time, but I subsequently visited hospitals in various parts of England. They had slow elevators and so on, and you could never move around the hospital quickly with any kind of emergency apparatus."

The success in the hospital wards made them believe success in the community would be possible. So it was the combination of a hospital's architectural layout and a physician's driving and persuasive personality that provided the impetus for this breakthrough. But one cannot discount the resuscitation infrastructure already in place: mouth-to-mouth ventilation, chest compression, and portable defibrillation. Without each of these three elements the Belfast program would have been a waste of time and effort.

The team reported the initial results of their program in the August 5, 1967 issue of The Lancet; their findings on 312 patients covered a 15-month period. Half the patients had MI and there were no deaths during transportation. Of ground-breaking importance was the information on 10 patients who had cardiac arrest. All had ventricular fibrillation; six arrests occurred after the arrival of the MCCU, and four occurred shortly before arrival of the ambulance. All 10 patients were resuscitated and admitted to the hospital. Five were subsequently discharged alive (ref). The article has historical importance because it served to stimulate pre-hospital emergency cardiac care programs throughout the world. As an historical footnote, August 1967 is exactly 200 years to the month from the founding of the Amsterdam Rescue Society. The rescue effort that began in 1767 in Amsterdam as an attempt to resuscitate drowning victims (the sudden death of the 18th century) finally culminated 2 centuries later in Belfast with a successful way to achieve resuscitation for cardiac arrest (the sudden death of the 20th century).

The Belfast system was established to reach patients with acute myocardial infarction. The resuscitated patients were those whose hearts fibrillated after the ambulance was at the scene or en route. The system reacted too slowly to resuscitate persons who fibrillated before the call was placed. In 1966, it was assumed that most cardiac deaths in the community were the result of acute myocardial infarction. It was not appreciated that ventricular fibrillation can occur without myocardial infarction and have only seconds of warning—or none at all.

The development of Emergency medical services
The extensive international readership of the Lancet helps explain why Pantridge's idea spread so rapidly to other countries. Within 2 years, similar physician staffed MCCU programs began in Australia and Europe. The first program in the United States was started in 1968 by William Grace out of St. Vincent's Hospital in Greenwich Village in New York City. The program was a clone of the Belfast program and utilized specially equipped ambulances with physicians on board to provide advanced resuscitation care directly at the scene of cardiac emergencies. Calls for medical emergencies in which chest pain was a complaint were passed on from the police 911 operator to the hospital. There an ambulance would fight New York traffic to arrive at the scene. Grace described the rather full ambulance and how it was sent:

"The personnel includes an attending physician, resident physician, emergency room nurse, ECG technician, as well as a student nurse observer, in addition to the driver and his assistant. This team is summoned from various points in the hospital to the emergency room by a personal paging system which each member of the team carries. This team has four and one half minutes to get to the emergency room, obtain their equipment and board the ambulance. Anyone who is not there within this time is left behind."&lt;ref&gt;Grace WJ, Chadbourn JA, The mobile coronary care unit. Diseases of the Chest, 1969;55:452-455&lt;/ref&gt;

In a scientific report of the St. Vincent's program, Grace described the experience with the first 161 patients (ref). Only two instances occurred in which the physician did not make the 4½-minute deadline and the ambulance left without the physician. The ambulance reached the scene usually within 14 minutes, plus of course the 4½-minute pre-response time. One call took 25 minutes owing to heavy traffic. Among the first group of patients seen by the MCCU were three patients treated for ventricular fibrillation. One of the three survived.

Grace took an innovative concept, imported from overseas, and made it work in his community. Physicians with defibrillators rushing through the city to reach a non-breathing, unconscious person whose heart had stopped were quite unusual by 1968 standards. However, the program was limited in vision, and although it could work in some communities, it was not nationally applicable. An evolution in prehospital emergency care was needed. Pantridge, Geddes, and Grace had broken the conceptual block of keeping resuscitations confined to hospitals. Now someone had to break a conceptual block that kept resuscitation in the hands of physicians. This called for a major change the personnel allowed to perform resuscitation.

The evolution from physician-staffed mobile intensive care units to paramedic-staffed units in the United States occurred independently and almost simultaneously in several communities. Two communities that led the way were Miami and Seattle, but others included Portland, Oregon, Los Angeles, and Columbus, Ohio. These communities were a major evolutional advance compared to the Belfast or New York City programs. Not only were paramedics used instead of physicians, but from their inception the programs were established to deal with the problem of sudden cardiac arrest. Pantridge's program was established primarily to reach the victim of MI fast and thereby prevent mortality in the vulnerable early stage of this event. Thus cardiac arrest was successfully treated only if it occurred as a complication of MI and only if the ambulance was already at the scene or en route. The new paramedic programs were far more nimble than physician-based programs and were specifically designed not only to treat the early stages of MI, but also to attempt resuscitation for sudden cardiac arrest wherever and whenever it occurred. Reversal of death itself would be a major purpose and goal of the new paramedic programs. Beck’s vision of treating “hearts too good to die” was becoming real.

Eugene Nagel, became aware of Pantridge's work in 1967. He believed that the physician-staffed model of prehospital care was not going to work for the United States in general or for Miami in particular. Physicians were too expensive to sit around fire stations waiting for calls, and if they had to be picked up in hospitals, it would take too long to arrive at the scene. When Nagel or his colleague James Hirschman, rode on the ambulance themselves they could, of course, defibrillate and provide medications, but they could not be present on all shifts. Nagel became convinced it was time to move away from a program using physicians to one staffed by paramedics.

Nagel moved incrementally. He did not think he could initially sell the idea of paramedics working alone, even if they had authorization to perform medical procedures signed by physicians. So instead his first step was to establish a radio link and telemetry between the paramedic fire fighters and the hospital. Nagel's had a hidden agenda in promoting telemetry. For Nagel it was the Trojan horse that gained him access through the legal impediments stopping fire fighters from defibrillating patients and administering medications. Nagel reasoned that if the fire department could send the ECG signal to the hospital via telemetry, then the fire fighters (with special training) could be authorized by the physician to administer needed drugs and procedures before arriving in the emergency department. He believed a paramedic at the scene was a legal extension of a physician. He recalled later, "We saw telemetry as the key to extending our treatment to outside the hospital where hitherto trying to legislate it was the dark side of the moon in those days. The telemetry looked like it might be the 'open sesame' to doing some treatment pre-hospital."

Nagel hoped to find support from the medical community; instead he only encountered discouragement. The theme of opposition to innovation seems a recurring one. Nagel recalled this opposition, “It was a rare doctor that favored us doing any of this stuff — very rare. We had incidents in the street when we were just sending an ECG, where doctors on the scene would tell the firemen to quit fooling around and haul the victim in.”

It should not be surprising that the medical directors of the various paramedic programs would remember the first resuscitation in their city. Nagel vividly recalled the first save of the Miami paramedic program. The collapse occurred near Station 1, on the fringe of downtown Miami, where the good part meets the bad part. He reminisced:

"There was a guy named Dan Jones who was then about 60 years old, who was a wino who lived in a fleabag in the bad part of town. Jones was well known to rescue. In June of '69 they got a call—man down—it was Jones. They put the paddles on him, he was in VF, started CPR, zapped him, he came back to sinus rhythm, brought him in to ER and three days later he was out and walking around. In gratitude, about a week later, he came down to Station 1, which he had never done before, and he said he would like to talk to the man who saved his life. They told me they had never seen Dan Jones in a clean shirt and sober, both of which he was that day. He would periodically come to the fire house and just say hello and he seemed to be sober. In my talks in those days I said this was the new cure for alcoholism. That was our first true save."

Pantridge's article also energized Leonard Cobb in Seattle. He knew the Seattle Fire Department was already involved in first aid and therefore approached the Fire Chief, Gordon Vickery, to propose a new training program to treat cardiac arrest. The fire department already had one of the United States' first computerized systems for documenting first aid runs. Cobb realized that this system could provide scientific documentation for the efficacy (or lack thereof) of Pantridge's suggestions and suggested to Vickery that they pool their knowledge and resources. Cobb and his colleagues then provided instruction and training in cardiac emergencies including cardiac arrest to volunteer fire fighters. The program became operational in March 1970, nine months after Nagel's first save in Miami. The mobile unit—and there was only one at first—was stationed outside the Harborview Hospital emergency department. As Cobb himself points out, the mobile unit was not the real innovation. Rather, it was the concept of a tiered response to medical emergencies. The idea was "that we would get someone out there quickly"—via the fire department's already existing mobile first aid units—"and then a secondary response would come from the mobile intensive coronary care unit." The beauty of the tiered response system was the efficient use of fire department personnel, which allowed aid personnel to reach the scene quickly (on an average of three minutes) to start CPR. Then a few minutes later the paramedics arrived to provide more definitive care such as defibrillation. In this way the brain could be kept alive until the electric shock converted the heart to a normal rhythm. After stabilization the paramedics would transport the patient to the hospital.

The Seattle paramedic program did more than pioneer paramedics and promote the tiered response system. It was the first program in the world to make citizens part of the emergency system. Cobb knew from data the program had collected that the sooner CPR was started, the better the chances of survival. He reasoned that the best way to ensure early initiation of CPR was to train the bystanders. Thus Cobb, with the support of Vickery, began a program in 1972 called Medic 2. Its goal was to train over 100,000 people in Seattle how to do CPR. Cobb recalled how the idea was first proposed:

One day he [Vickery] said, "Look, if it's so important to get CPR started quickly and if firemen come around to do it, it can't be that complicated that other folks couldn't also learn—firemen are not created by God to do CPR. You could train the public." I said, "That sounds like a very good idea." Shortly afterwards things started.

Cobb decided to use an abbreviated course of training. "We weren't going to do it by traditional ways where they had to come for 20 hours (of training). So they had to do it at one sitting—how long will people participate?—well, maybe three hours and that's pretty much the way it was.” Cobb cautiously did not state how long it would take to train 100,000 people. He had no idea. In fact it took only a few years and by the 20th anniversary of the citizen training program over half a million people in Seattle and the surrounding suburbs had received training in CPR.

Some people were sceptical about mass citizen training in CPR; indeed, many felt the potential for harm was too great to allow such a procedure in the hands of laypersons. The skeptics also had the support of national medical organizations. The alarmist voices were stilled by some fortunate saves. Cobb recalled one resuscitation soon after the citizen training program began. "In March 1973 there were these kids playing golf at Jackson Park. They came across a victim a quarter of a mile from the clubhouse." The man was unconscious and not breathing; later it was confirmed that he was in ventricular fibrillation. "But these kids had taken the [CPR] course over at the local high school. Two or three of them started doing CPR and the other kid ran off and phoned the fire department. Shortly they came with the aid car and Medic 1 screaming over the fairways." Cobb concluded, "They got him started up again. He survived; he's alive today [1990]. That was a very convincing story. I didn't mind it being written up in the Reader's Digest."

The decade of the 1960s started with the development of CPR. By the end of the decade, paramedic programs were operating in Miami and Seattle (and Portland, Columbus, and Los Angeles). A common denominator to all the cities was a physician who saw the problem of out-of-hospital cardiac deaths, decided not to accept the irreversibility of death, and started doing something about it.

Recent developments in CPR
By the early 1970s CPR, defibrillation, and a rapid means to provide prehospital care were all in place. The structure to resuscitate sudden death victims had been built and was proving successful. That most of the world did not have this structure in place in the 1970s was largely due to lack of diffusion and spread of the ideas, rather than the impossibility of carrying them out.

However, the story of resuscitation does not stop in the early 1970s. Major advances have continued. In 1980 the first program to train EMTs to perform defibrillation began in King County, Washington, and similar programs spread throughout the United States. This training required 10 hours, and in the first demonstration project, survival from ventricular fibrillation increased from 7% to 26% (ref). In 1984 the first program with fire fighter EMTs using automated external defibrillators (AEDs) also began in King County, Washington. The use of AEDs simplified the training of EMTs and thus allowed the procedure to spread more rapidly throughout communities. Automated external defibrillators require considerably less training time compared to manual defibrillators since the EMT does not have to interpret the cardiac rhythm.

The idea for an automated defibrillator was first conceived by Dr. Arch Diack, a surgeon in Portland, Oregon. His prototype, literally assembled in a basement, utilized a unique defibrillatory pathway – tongue to chest. There was a breath detector that was a safeguard to prevent shocking breathing persons. The electrode was essentially a rate counter, far cruder than today’s sophisticated VF detectors. The production model weighed 35 pounds and gave verbal instructions. It was an idea ahead of its time. Most people viewed it as a curiosity. By the late 1980s, however, other manufacturers entered the field leading to the automated external defibrillators (AEDs) we have today. Current AEDs, like regular defibrillators, use electrode pads attached to the chest. AEDs are programmed to guide the operator (with a series of voice prompts) through the procedure. The pads once attached automatically detect the type of heart rhythm and if VF is present the AED instructs the operator to press a button (usually flashing red) to shock the patient. From EMT defibrillation with AEDs, there was a natural and logical progression to first responder defibrillation (AEDs used by police or security personnel), next widespread Public Access Defibrillation (AEDs used by lay persons in public locations such as airports, schools, exercise facilities, etc.) and finally home AED including the opportunity to purchase AEDs over the counter without a prescription.

In 1981 a program to provide telephone instructions in CPR began in King County, Washington. This program used the emergency dispatchers to give instant directions while the fire department EMT personnel were en route to the scene. This demonstration project increased the rate of bystander-provided CPR by 50%. Dispatcher-assisted CPR is now standard care for dispatcher centers throughout the United States and in other countries such as Israel, Great Britain, Sweden, and Norway.

The American Heart Association uses a metaphor of four links in a chain to describe the elements of successful resuscitation. These links are early access (recognizing cardiac arrest and calling 911), early CPR, early defibrillation, and early advanced care (such as medications, endotracheal intubation) The early paramedic programs were all designed to provide CPR, defibrillation, and advanced care quickly enough to resuscitate patients in cardiac arrest.