An artificial heart is a device that replaces the heart. Artificial hearts are typically used as a bridge to heart transplantation, but ongoing research aims to develop a device that could permanently replace the heart when a transplant—whether from a deceased human or, experimentally, from a genetically engineered pig—is unavailable or not viable. , there are two commercially available full artificial heart devices; both are intended for temporary use (less than a year) for patients with total heart failure who are awaiting a human heart transplant.
Although other similar inventions preceded it from the late 1940s, the first artificial heart to be successfully implanted in a human was the Jarvik-7 in 1982, designed by a team including Willem Johan Kolff, William DeVries and Robert Jarvik.
An artificial heart is distinct from a ventricular assist device (VAD; for either one or both of the ventricles, the heart's lower chambers), which may also be a permanent solution, or the intra-aortic balloon pump – both devices are designed to support a failing heart. It is also distinct from a cardiopulmonary bypass machine, which is an external device used to provide the functions of both the heart and lungs, used only for a few hours at a time, most commonly during cardiac surgery. It is also distinct from a ventilator, used to support failing lungs, or the extracorporeal membrane oxygenation (ECMO), which is used to support those with both inadequate heart and lung function for up to days or weeks, unlike the bypass machine.
History
Origins A synthetic replacement for the heart has long been a major goal of modern medicine. A functional artificial heart could reduce the need for heart transplantation, as the demand for donor organs exceeds supply.
Although the heart is conceptually a pump, it embodies subtleties that defy straightforward emulation with synthetic materials and power supplies. Artificial hearts have historically had issues from both a biomedical standpoint, regarding clotting and foreign object rejection, as well as longevity and practicality, regarding the lifespan of the device as well as the equipment required to run it.
Since the inception of the device, artificial hearts have been continually improved as medical technology has. More recent devices, such as the Carmat heart, have sought to improve upon their predecessors by reducing complications resultant from device implant, such as foreign-body rejection and thrombus.
Early development The first artificial heart was made by the Soviet scientist Vladimir Demikhov in 1938. It was implanted in a dog.
On 2 July 1952, 41-year-old Henry Opitek, suffering from shortness of breath, made medical history at Harper University Hospital at Wayne State University in Michigan. The Dodrill-GMR heart machine, considered to be the first operational mechanical heart, was successfully used while performing heart surgery. and Ongoing research was done on calves at Hershey Medical Center, Animal Research Facility, in Hershey, Pennsylvania, during the 1970s.
Forest Dewey Dodrill, working closely with Matthew Dudley, used the machine in 1952 to bypass Henry Opitek's left ventricle for 50 minutes while he opened the patient's left atrium and worked to repair the mitral valve. In Dodrill's post-operative report, he notes, "To our knowledge, this is the first instance of survival of a patient when a mechanical heart mechanism was used to take over the complete body function of maintaining the blood supply of the body while the heart was open and operated on."
A heart–lung machine was first used in 1953 during a successful open heart surgery. John Heysham Gibbon, the inventor of the machine, performed the operation and developed the heart–lung substitute himself.
Following these advances, scientific interest for the development of a solution for heart disease developed in numerous research groups worldwide.
Early designs of total artificial hearts In 1949, a precursor to the modern artificial heart pump was built by doctors William Sewell and William Glenn of the Yale School of Medicine using an Erector Set, assorted odds and ends, and dime-store toys. The external pump successfully bypassed the heart of a dog for more than an hour.Lavietes, Stuart. William Glenn, 88, Surgeon Who Invented Heart Procedure , The New York Times, 17 March 2003. Accessed 21 May 2009.
On 12 December 1957, Willem Johan Kolff, the world's most prolific inventor of artificial organs, implanted an artificial heart into a dog at Cleveland Clinic. The dog lived for 90 minutes.
In 1958, Domingo Liotta initiated the studies of TAH (Total Artificial Heart) replacement at Lyon, France, and in 1959–60 at the National University of Córdoba, Argentina. He presented his work at the meeting of the American Society for Artificial Internal Organs held in Atlantic City in March 1961. At that meeting, Liotta described the implantation of three types of orthotopic (inside the pericardial sac) TAHs in dogs, each of which used a different source of external energy: an implantable electric motor, an implantable rotating pump with an external electric motor, and a pneumatic pump.
Paul Winchell designed a model of artificial heart with the assistance of Henry Heimlich (the inventor of the Heimlich maneuver) and submitted a patent for a mechanically driven artificial heart implementing a cam driven roller mechanism to compress flexible bags containing blood, on 6 February 1961. This is contrary to the popular claim that Winchell submitted the patent in the summer of 1956, as well as contrary to the claim that Winchell "invented" the artificial heart. In fact, two patents existed prior to Winchell's submission. These patents were filed 10 April 1956, and 17 April 1959, respectively. Winchell also claims that the design within his patent was used in later models of the Jarvik hearts, a claim in which Robert Jarvik, the principle designer of those hearts, denies on the basis that his pneumatically driven hearts share little in common with Winchell's mechanically actuated patent.
In 1964, the National Institutes of Health started the Artificial Heart Program, with the goal of putting an artificial heart into a human by the end of the decade.Sandeep Jauhar: The Artificial Heart. New England Journal of Medicine (2004): 542–544. The purpose of the program was to develop an implantable artificial heart, including the power source, to replace a failing heart.
In February 1966, Adrian Kantrowitz rose to international prominence when he performed the world's first permanent implantation of a partial mechanical heart (left ventricular assist device) at Maimonides Medical Center.
In 1967, Kolff left Cleveland Clinic to start the Division of Artificial Organs at the University of Utah and pursue his work on the artificial heart. In 1973, a calf named Tony survived for 30 days on an early Kolff heart. In 1975, a bull named Burk survived 90 days on the artificial heart. In 1976, a calf named Abebe lived for 184 days on the Jarvik 5 artificial heart. In 1981, a calf named Alfred Lord Tennyson lived for 268 days on the Jarvik 5.
Over the years, more than 200 physicians, engineers, students and faculty developed, tested and improved Kolff's artificial heart. To help manage his many endeavors, Kolff assigned project managers. Each project was named after its manager. Graduate student Robert Jarvik was the project manager for the artificial heart projects, from which the Jarvik line of artificial hearts get their name. There, physician-engineer Clifford Kwan-Gett invented two components of an integrated pneumatic artificial heart system: a ventricle with hemispherical diaphragms that did not crush red blood cells (a problem with previous artificial hearts) and an external heart driver that inherently regulated blood flow without needing complex control systems. Jarvik also combined several modifications: an ovoid shape to fit inside the human chest, a more blood-compatible polyurethane developed by biomedical engineer Donald Lyman, and a fabrication method by Kwan-Gett that made the inside of the ventricles smooth and seamless to reduce dangerous stroke-causing blood clots.
First clinical implantation of a total artificial heart
On 4 April 1969, Domingo Liotta and Denton A. Cooley replaced a dying man's heart with a mechanical heart inside the chest at The Texas Heart Institute in Houston as a bridge for a transplant. The man woke up and began to recover. After 64 hours, the pneumatic-powered artificial heart was removed and replaced by a donor heart. However thirty-two hours after transplantation, the man died of what was later proved to be an acute pulmonary infection, extended to both lungs, caused by fungi, most likely caused by an immunosuppressive drug complication.Orthotopic cardiac prosthesis for two-staged cardiac replacement. Am J Cardio 1969; 24:723–730.
The original prototype of Liotta-Cooley artificial heart used in this historic operation is prominently displayed in the Smithsonian Institution's National Museum of American History "Treasures of American History" exhibit in Washington, D.C."Treasures of American History" , National Museum of American History
First clinical applications of a permanent pneumatic total artificial heart The first clinical use of an artificial heart designed for permanent implantation rather than a bridge to transplant occurred in 1982 at the University of Utah.
In 1981, William DeVries submitted a request to the FDA for permission to implant the Jarvik-7 into a human being. On 1 December 1982, William DeVries implanted the Jarvik-7 artificial heart into Barney Clark, a retired dentist from Seattle who had severe congestive heart failure. Clark's case was highly publicized and received much media attention, garnering attention from television networks, newspapers and periodicals. Clark lived for 112 days tethered to the UtahDrive pneumatic drive console, a device weighing some . During that time Clark required several re-operations, suffered seizures, experienced prolonged periods of confusion and a number of instances of bleeding and asked several times to be allowed to die. Clark, however, still believed his being part of the initial experiment was an important contribution to medicine, and maintained an overall positive outlook on his condition. Clark died on 23 March 1983, of multiorgan system failure. Despite the complications, DeVries considered Clark's case a success.Spare Parts: Organ Replacement in American Society. Renee C. Fox and Judith P. Swazey. New York: Oxford University Press; 1992, pp. 102–104