CPR wasn’t a single discovery. It came together in pieces across the late 1950s, when three separate breakthroughs in rescue breathing, chest compressions, and their combination converged into the lifesaving technique used today. The person who stitched it all together was an Austrian-born physician named Peter Safar, often called the father of CPR.
Before CPR: Crude Attempts at Resuscitation
For most of human history, people who stopped breathing or whose hearts stopped simply died. The few resuscitation methods that existed were mechanical and unreliable. In 1858, London physician Henry Silvester developed a chest-pressure arm-lift method: raise the patient’s arms overhead to expand the chest, then cross them over the chest to force air out. Variations on this approach persisted for nearly a century, including prone-position techniques where rescuers pressed on a person’s back.
These methods moved far less air than the lungs actually needed. They also required the patient to be positioned in specific ways that weren’t always practical in an emergency. None of them addressed what to do when the heart itself stopped beating. That problem wouldn’t be solved until the electrical age.
Rescue Breathing: The 1950s Breakthrough
The mouth-to-mouth technique that most people associate with CPR was validated through a series of surprisingly bold experiments in the mid-1950s. Peter Safar, then working in Baltimore, wanted to prove that exhaled air from a rescuer contained enough oxygen to keep a victim alive. To test this, he paralyzed healthy volunteers with drugs that temporarily stopped their ability to breathe on their own, then had untrained people ventilate them using only mouth-to-mouth contact.
Working alongside physicians James Elam and Archer Gordon, Safar demonstrated two things. First, the prone-position methods that had been standard for decades did not reliably keep a person’s airway open. Second, a rescuer’s exhaled breath delivered plenty of oxygen for effective artificial ventilation. Safar also figured out the mechanics that made it work: extending the neck and supporting the jaw to keep the airway clear. These findings effectively rendered a century of arm-lifting and back-pressing techniques obsolete.
Chest Compressions: An Accidental Discovery
The other half of CPR, external chest compressions, came from an entirely different field. At Johns Hopkins University, electrical engineer William Kouwenhoven had been studying defibrillation, using electrical shocks to restart the heart. During those experiments, his team noticed something unexpected: when they pressed defibrillator paddles firmly against a dog’s chest, the pressure alone produced a small but measurable pulse.
Kouwenhoven, along with engineer Guy Knickerbocker and surgeon James Jude, pursued that observation. By 1958, they had confirmed that rhythmic external chest compressions could generate enough artificial circulation to keep blood flowing to the brain and organs during cardiac arrest, not just in animals but in humans. Before this discovery, the only way to manually pump a stopped heart was to cut open the chest and squeeze it directly, a procedure only possible in an operating room.
Putting the Pieces Together
Peter Safar recognized that rescue breathing and chest compressions were two halves of the same solution. A person in cardiac arrest needs both air in the lungs and blood moving through the body. By 1960, Safar had combined the mouth-to-mouth technique with the Hopkins team’s chest compressions into a single, teachable sequence. He called it the ABCs of resuscitation: Airway, Breathing, Circulation. The term “cardiopulmonary resuscitation,” or CPR, followed shortly after.
What made Safar’s contribution so significant wasn’t just the combination itself. It was his insistence that ordinary people, not only doctors, could learn and perform it. He worked with Archer Gordon to develop training methods using mannequins, making mass education possible for the first time. The famous “Resusci Anne” training dummy, modeled after the death mask of an unidentified woman pulled from the Seine River in Paris, became the face of CPR training worldwide.
From Hospital Technique to Public Skill
Through the 1960s, CPR moved rapidly from medical journals into public awareness. The American Heart Association endorsed the technique and began promoting standardized training. For decades, the standard sequence followed Safar’s original ABC order: open the airway first, deliver rescue breaths, then begin chest compressions.
That sequence held until 2010, when the American Heart Association made a major change, flipping the order to CAB: compressions first, then airway, then breathing. The reasoning was practical. Most cardiac arrests in adults involve a heart rhythm problem, not an airway problem, which means chest compressions and defibrillation are the most critical early interventions. Under the old ABC sequence, compressions were often delayed while rescuers struggled to open the airway or position themselves for mouth-to-mouth breathing. Since opening an airway and delivering breaths are the steps rescuers find most difficult, the old order was actually discouraging bystanders from starting CPR at all.
The Rise of Hands-Only CPR
An even bigger shift came with the recognition that chest compressions alone could be nearly as effective as traditional CPR for many cardiac arrests. This idea had been circulating among researchers since the late 1990s. Animal studies showed that when cardiac arrest lasted less than six minutes, adding rescue breaths to chest compressions did not improve outcomes compared with compressions alone. Human data told a similar story: analysis from a national out-of-hospital CPR registry found no survival advantage when bystanders added mouth-to-mouth ventilation to chest compressions.
By 2007, three large observational studies had confirmed that omitting rescue breaths did not negatively affect survival, even when researchers looked at long-term neurological outcomes at 30 days and one year. In 2008, the American Heart Association formally endorsed “Hands-Only CPR” for bystanders who witness an adult collapse. The message was simple: call 911 and push hard and fast in the center of the chest. No mouth contact required.
This was a turning point for public willingness to act. Many bystanders had been reluctant to perform mouth-to-mouth on a stranger. Removing that barrier meant more people in cardiac arrest would receive some form of CPR before paramedics arrived, and any CPR is dramatically better than none.
Why the History Matters
CPR’s development is a story of convergence. Rescue breathing came from anesthesiologists studying airway management. Chest compressions came from electrical engineers studying defibrillation. The combination came from a physician who saw how the pieces fit and believed the technique belonged in every citizen’s hands, not locked inside hospitals. Each step built on an observation that could easily have been overlooked: that exhaled air carries enough oxygen, that external pressure can move blood through a stopped heart, that ordinary people can do both effectively with minimal training. The technique continues to evolve, but the core insight from the late 1950s remains unchanged. When someone’s heart stops, the people standing nearest have the power to keep them alive.