Charles Lindbergh’s Artificial Heart
Just a few years after his historic solo flight across the Atlantic, the aviator developed an ingenious predecessor to today’s man-made hearts
On a shelf in a largely ignored basement display case at Rockefeller University sit a variety of medical devices that have been produced by that institution’s laboratories over the past half century. One of them is especially awkward looking —a glass cylinder that rises two feet before sprouting a seemingly haphazard array of tubes. Its glass innards of more tubes and smaller chambers suggest the workings of some unidentifiable life-form.
It was alive once, in a manner of speaking. It is the world’s first artificial heart, unveiled fifty years ago with the publication of an article in Science magazine by its inventor, Charles A. Lindbergh, the man who became an instant hero in 1927 with his flight across the Atlantic. Descendants of the Lindbergh heart—in spirit if not direct lineage—have kept alive a handful of patients with diseased hearts in recent months.
The heart worked in connection with a sophisticated rotating valve, a thick disk enclosed in glass, with a tunnel bored through its diameter and two concavities of different sizes carved out of its circumference. The valve rotated in precise imitation of the systolic and the diastolic pressure that the beating of a natural heart exerts on arteries.
“That valve was an incredible piece of ingenuity,” reflects Merrill Chase, professor emeritus at Rockefeller University. Chase is the only living witness to Lindbergh’s four-year struggle to perfect the heart for the brilliant and controversial French surgeon Alexis Carrel, who was a staff member of what was then called the Rockefeller Institute for Medical Research. “The pump was a beautiful machine, but this was its key. Without the alternating pressure Carrel just couldn’t have studied organs with any degree of meaning.”
Lindbergh’s heart was never meant to be placed in a body; rather it was designed to keep organs alive for an indefinite period outside the body, and Lindbergh referred to it as a perfusion pump. The New York Times called it an artificial heart, and the name stuck. Time magazine described it as “a twist of vitrified bowel oozing out of a clear glass bottle.” Far bulkier than the Jarvik 7 in use today, it looked in profile like an abstract sculptor’s interpretation of a heron.
The Lindbergh invention worked in this way: an organ from a freshly killed animal—usually a fowl or a cat that had been bled to death—was placed in the main chamber, and a glass tube fitted to its main artery. The chamber was then sealed, and the machine, placed in an incubator, was activated. Air hissed through tubes and into the rotating valve, whose concavities forced gas to flow into the glass apparatus in alternating pulses, pushing artificial blood up from the base of the machine into the organ. After flowing through it, the fluid drained out by gravity and fell into a pressure-equalization chamber before returning to the lower reservoir chamber for recycling. The artificial blood, developed by a member of the Rockefeller Institute, consisted of actual blood serum with growth-activating solutions added and was colored red so it could easily be traced on its path through the organ.
Though Lindbergh’s invention was a much quieter affair than his transatlantic flight (it is not even mentioned in The Encyclopaedia Britannica ), it was no less significant. Both accomplishments stemmed from an incurable fascination with the way things work that first became evident during his childhood in Little Falls, Minnesota. A farm boy, he could dismantle and reassemble the working parts of a shotgun before he learned to read, according to his biographer, Kenneth S. Davis. Machines fascinated him. “There is evidence,” writes Davis in The Hero: Charles A. Lindbergh and the American Dream, “that they became more ‘real’ to him, in a living way, than most people did; his imagination seemed to endow them with individual personalities, inspiring in him personal likes and dislikes as he tinkered with them and tested their performance.”
The local hardware dealer was so amazed by the boy’s intuitive knowledge of mechanics that he offered him the run of his workshop, an opportunity that encouraged his love of tinkering. Lindbergh was a lackluster and rebellious student, but he enrolled at the University of Wisconsin because it had a strong mechanical-engineering department. He was more interested in motorcycle riding than studying and seemed entranced by the control he could exert over the machine. Davis recounts one hair-raising incident in which Lindbergh claimed to friends that he could race down a steep hill and, without braking, make a sharp turn at the bottom. He failed the first time; his motorcycle landed in a gutter, and he in a fence. Extricating himself, he insisted that if he had accelerated a bit more before making the turn, he would have come through unscathed. He was right. The second time, he gunned the engine at the bottom of the hill and just made the turn.
The young Lindbergh loved to take risks, and in those days aviation was the ultimate risk. Frustrated by academic regulations, he dropped out of the university in his sophomore year and went to the Nebraska Aircraft Corporation, the nearest place he could experience the biggest thrill of all—flying in the open cockpit of a biplane. From the moment, on April 9, 1922, when a pilot took him aloft for the first time, Lindbergh devoted the rest of his life to promoting aviation, a path that led from barnstorming through the Midwest and flying a mail route to his transatlantic flight.
Though he had no training in physiology or biology, Lindbergh pursued the invention of his artificial heart with equal fervor. In 1930 a relative of his was very ill with a cardiac disease. Doctors told Lindbergh that as the heart could not be stopped, nothing could be done to repair it. This information, while disheartening, was an inspiration. “If the circulation of blood could be maintained artificially for a few minutes,” Lindbergh wrote, “why couldn’t the heart be stopped and its lesions removed by the surgeon’s scalpel?”
Alexis Carrel was interested in the same question in connection with his research. He had perfected a technique of keeping cells and tissue alive by bathing them in nutrient solutions, but success at keeping an entire organ ^ alive eluded him, as it had many others. A mutual | acquaintance introduced Lindbergh to Carrel in I 1930. The two men admired each other from the outset and developed a deep friendship over the next decade. At their first meeting Carrel explained the difficulties of artificially maintaining circulation: keeping red blood cells alive was one; preventing infection was another.
A pioneer in vascular surgery, Carrel had received a Nobel Prize in 1912 for his revolutionary technique of transplanting organs and suturing blood vessels. He had also achieved fame for experiments in growing connective tissue cells from embryonic chicken hearts that led him to believe that cells were immortal if fed the proper nutrients. Later this claim aroused suspicion, and it is now largely refuted. During World War I Carrel and a chemist named Drysdale Dakin developed a sterile cleansing solution that they used on Europe’s battlefields. The discovery saved countless limbs and lives.
As respected as Carrel was, he was also viewed as an eccentric who flirted with arcane mysticism. His operating room was painted entirely in black, illuminated only by a huge skylight. Much to the delight of the press, everyone who entered had to don black robes and hoods, while Carrel wore a white cap. Merrill Chase recalls a time when he watched Carrel perform experimental surgery: “His assistants were lined against one wall, their hands tucked into the folds of their robes and their faces covered except for eye slits. They were motionless, moving only if called upon to assist in the surgery.” Ironically, an increasing number of surgeons today have begun wearing dark surgical gowns in an effort to diminish light reflection.
On the eve of World War II Carrel alienated admirers by proclaiming that all men were not created equal. He called for a “High Council of Doctors” to oversee a reorganization of society in which the characteristics of “civilized nations” would be promoted, and he made it no secret that he thought himself an ideal candidate for the council. Prevailing racial theories of the time were at the heart of some of his more bizarre pronouncements.
The mystery surrounding Carrel extended to his relationship with Lindbergh. The public wondered what Lindbergh was doing at the prestigious institute, and rumors sprang up that the surgeon was preparing to replace Lindbergh’s heart with an indestructible one. In fact, Carrel had imported a German engineer to design a pump to keep organs alive, but the effort had failed. Lindbergh asked to see the pump the German had made and two weeks later returned to Carrel’s laboratory with a model for a glass pump of his own design, which he had commissioned a glass blower at Princeton University to create. So impressed was Carrel that he opened his laboratory to Lindbergh, who soon came up with a new design, an upright glass spiral that when rocked forced blood upward and through an organ’s arteries upon its return. This failed as a heart but could keep a segment of artery alive for a month before infection set in. During the succeeding three years Lindbergh produced two more designs. Though each failed, his efforts were not futile, for in the course of his experiments he invented several other devices, some of them still in use today. The most noteworthy is a centrifuge that separates blood plasma from serum and washes the cells in a continuous operation.
Lindbergh was working on that project when Merrill Chase, then doing immunological research at the institute, first had lunch with him. “As soon as we sat down,” Professor Chase recalls, “he began talking about what was wrong with centrifuges. His most salient point was that they were all made of bronze and at certain speeds bronze will crack. I was amazed at his knowledge.”
While Lindbergh was trying to perfect a pump design, his first son, Charles Augustus, Jr., two years old, was kidnapped and, three months later, found dead. A media storm surrounded the inventor for four years, until Bruno Hauptmann was executed for the crime. Through it all Lindbergh continued his work at the Rockefeller Institute. By the time he and Carrel unveiled the perfusion pump, in 1935, they had performed twenty-six experiments with it on a variety of animal organs. Infection had set in only twice. Changes in the organs could readily be observed when the nutrients in the artificial blood were altered. Thyroids and ovaries had grown rapidly when fed growth-promoting substances—one ovary had more than trebled in weight in five days. The pump had also generated insulin from pancreases and thyroid hormone from thyroids. Organs had been kept alive on it for up to twenty-one days; there was no reason, Carrel and Lindbergh said, why they could not be sustained indefinitely.
Carrel extolled the virtues of the pump to an expectant press. He foresaw a time when organs in Lindbergh pumps would produce enough hormones for use in treating patients. He wrote, “Organs removed from the human body in the course of an operation or soon after death, could be revived in the Lindbergh pump … ,” and added that perhaps one day, “diseased organs [or limbs] could be removed from the body and placed in the Lindbergh pump as patients are placed in the hospital. Then they could be treated far more energetically than within the organism, and if cured replanted in the patient.”
No experiments were ever performed to fulfill these hopes. There is no record that Carrel even tried to determine how long the artificial heart would keep an organ alive. In the late 1930s he seemed to lose interest in the heart’s possibilities and took up philosophizing about the need to reorganize society. His book Man, the Unknown , in which he set forth his ideas for the High Council of Doctors, sold nine hundred thousand copies. Eventually, most of the twenty-or-so pumps that were created were destroyed in order to salvage the platinum in their filters. Shortly before the outbreak of World War II, Carrel retired from the Rockefeller Institute and returned to France, where he lived on an island off Brittany. Lindbergh and his wife and their two sons, still close friends of Carrel, purchased a neighboring island on which they lived until their return to the United States in 1940. During the war the Germans allowed Carrel to set up the French Foundation for the Study of Human Problems, in Paris. He died in 1944 of a heart attack.
Several efforts were made in the 1940s to advance Carrel’s research by using pumps of various designs to replace the heart’s circulation in animals, but the glass or stainless steel from which they were made caused blood clots and destroyed red blood cells. These problems were partially overcome with the introduction of synthetic materials following the War. Nevertheless clotting and cell destruction have remained major barriers in the progress of artificial heart research down to the present—as evidenced by the strokes that William Schroeder suffered while supported by the implantable Jarvik 7 heart, which has a polyurethane inner surface reinforced with Dacron and uses pyrolytic carbon disks as valves.
Even before such materials were perfected, efforts to implement artificial hearts continued. Externally located blood pumps were developed along with oxygenators so that the circulation to the heart and lungs could be stopped and the heart emptied of blood. This allowed open heart surgery. In 1953 Dr. John Gibbon of Philadelphia became the first surgeon to successfully close a hole between two chambers of the heart using a heart-lung machine to maintain circulation. The natural heart of a dog was replaced by an internal pump with valves in 1957, and the animal survived for ninety minutes. But progress on an internal artificial heart for humans came to a near halt in 1969, following the first implant, by Dr. Denton Cooley, in Houston. That heart’s air-driven pumps kept a patient alive for three days prior to the implantation of a human heart, which replaced the device in his chest. The patient died, however, shortly thereafter. The Food and Drug Administration approved Dr. Robert K. Jarvik’s artificial heart design in 1982, and in 1985 it approved an artificial heart made by Dr. William Pierce in Hershey, Pennsylvania.
What was the significance of the Lindbergh heart? While it cannot be thought of as a direct link in the effort that led to the Jarvik 7, it was an inspiration that showed that life could be sustained by a machine that works very much like the heart. Today there is little use for such an apparatus. Research emphasis has shifted back to ferreting out the intricacies of cells and tissues, and organs can now be exhaustively studied and operated on within the body. But this does not mean that the pump will forever be a neglected museum piece. “The technique was so grand,” says Professor Chase, “that someday it is bound to be reintroduced to further the study of organisms.”