Artificial heart

An AbioCor artificial heart

Artificial heart
From Wikipedia, the free encyclopedia


An artificial heart is a prosthetic device that is implanted into the body to replace the original biological heart. It is distinct from a cardiac pump, which is an external device used to provide the functions of both the heart and the lungs. Thus, the cardiac pump need not be connected to both blood circuits. Also, a cardiac pump is only suitable for use not longer than a few hours, while for the artificial heart the current record is 17 months.
This synthetic replacement for an organic mammalian heart (usually human), remains one of the long-sought Holy Grails of modern medicine. Although the heart is conceptually a simple organ (basically a muscle that functions as a pump), it embodies complex subtleties that defy straightforward emulation using synthetic materials and power supplies. The obvious benefit of a functional artificial heart would be to lower the need for heart transplants, because the demand for donor hearts (as it is for all organs) always greatly exceeds supply. A heart-lung machine was used in 1953 during the first successful open heart surgery. Dr. John Heysham Gibbon performed the operation and developed the heart-lung substitute himself. Whether this could be counted as an artificial heart is a subject of debate. In either case, the first official artificial heart that was patented was done so by Paul Winchell in 1963. Winchell subsequently assigned the patent to the University of Utah, where Robert Jarvik ultimately used it as the model for his Jarvik-7. One of the innovations of the Jarvik-7 was the inner coating of rough material, the contribution of a man named David Gernes. This coating helped the blood to clot and coat the inside of the device, enabling a more natural blood flow. Early attempts prior to the Jarvik-7 were disappointing; hosts died within hours or days and/or suffered massive foreign-body rejection problems. Jarvik's human designs were more impressive but his patients succumbed as well; his first Jarvik-7 patient, 61-year-old retired dentist Barney Clark, survived for 112 days after it was implanted at the University of Utah on December 2, 1982. Another problem is that an artificial heart requires an external power supply such as a battery pack worn on the patient's waist; no design so far has been able to use the body's own natural biological energy.
After about 90 people received the Jarvik device, the artificial hearts were banned for permanent use in patients with heart failure, because most of the recipients could not live more than half a year. However, it is used temporarily for some heart transplantation candidates who cannot find a natural heart immediately but urgently need an efficiently working heart.
On July 2, 2001, Robert Tools received the first completely self-contained artificial heart transplant in a surgery done by University of Louisville doctors at Jewish Hospital in Louisville, Kentucky. It is called the AbioCor Implantable Replacement Heart. Tom Christerson survived for 17 months after his artificial heart transplant.
The Syncardia CardioWest total artificial heart (CW-TAH) was developed by University of Arizona researchers and approved for bridge-to-transplant use in 2004. It is the first implantable artificial heart to be approved by the U.S. Food and Drug Administration. The longest CW-TAH implantation went 602 days (approximately 20 months.) (1)
The AbioMed company of Danvers, Massachusetts produced the AbioCor device, which on September 6, 2006 became the first fully implantable artificial heart to be approved, albeit under Humanitarian Use Device rules.
Most doctors are confident that with increased understanding of the heart and continuing improvements in prosthetics engineering, computer science, electronics, battery technology, fuel cells, etc. that the practical artificial heart will be a reality sometime in the 21st century.
In fiction
The earliest example of a fictional artificial heart is the French pulp hero the Nyctalope.
In the fictional Star Trek universe, Captain Jean-Luc Picard had an artificial heart implanted in 2328, which was later replaced twice. Joseph Sisko, father of Benjamin Sisko, had several artificial organs, including a new aorta he received in 2372.
The British science fiction series Space: 1999 had a character, Victor Bergman (portrayed by Barry Morse), with an artificial heart. He was able to modify its rate of operation with a wrist-worn device.
The novels of Philip K. Dick feature the use of 'artiforgs' or artificial organs.
The German heavy metal band Accept wrote about artificial hearts in their album "Metal Heart" (1985).
In the 1987 movie Robocop, there is a commercial for an artificial heart clinic called "The Family Heart Center" where surgeons operate on persons and implant artificial hearts from "the complete line of hearts by Jensen and Yamaha," encouraging its customers "You pick the heart!" These hearts come with extended warranties, financing, and qualify for "health tax credit."
References
(1) N. Gray, Jr, C. Selzman. Current status of the total artificial heart. American Heart Journal, 152, (1):4-10. July 2006. link
FDA Approval Press Release September 5, 2006.
Further Reading
George B. Griffenhagen and Calvin H. Hughes. The history of the mechanical heart. Smithsonian Report for 1955, (Pub. 4241): 339-356, 1956.
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