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heart, artificial,external or surgically implanted mechanical device designed to replace a patient's diseased heartheart,
muscular organ that pumps blood to all parts of the body. The rhythmic beating of the heart is a ceaseless activity, lasting from before birth to the end of life. Anatomy and Function
The human heart is a pear-shaped structure about the size of a fist.
..... Click the link for more information. . The first one used on a human being, the Jarvik-7, was implanted (1982) in Barney Clark, who lived for 112 days; another patient, William Schroeder, lived 620 days. Two major drawbacks of the Jarvik-7 were the danger of strokestroke,
destruction of brain tissue as a result of intracerebral hemorrhage or infarction caused by thrombosis (clotting) or embolus (obstruction in a blood vessel caused by clotted blood or other foreign matter circulating in the bloodstream); formerly called apoplexy.
..... Click the link for more information. from clots formed in the artificial heart and the need for the patient to be hooked to the external air compressor that powered the pump. By 1989 such devices had largely become a bridge to human heart transplants (see transplantation, medicaltransplantation, medical,
surgical procedure by which a tissue or organ is removed and replaced by a corresponding part, usually from another part of the body or from another individual.
..... Click the link for more information. ).
Beginning 2001, however, a second type of artificial heart, the AbioCor, was implanted in a number of patients. Unlike the Jarvik-7, the AbioCor is powered by electrical energy that is transmitted from a battery across the skin to an internal coil and backup battery. Because an opening in the skin is not needed to allow passage for tubes or wires, the risk of infection is greatly reduced. In addition, the external battery pack is designed to worn on a belt or suspenders, enabling the patient to be mobile. On average, the patients who received the heart from 2001 to 2004 and survived the operation lived for five months; the longest lived not quite 17 months. In 2006 the AbioCor was approved for use in patients who do not qualify for a heart transplant if their life expectancy as a result of heart failure is less than month; the device is also approved as a temporary measure for patients awaiting a transplant. A number of other artificial hearts have since been implanted temporarily or experimentally in patients, with varying degrees of success.
A related device, the ventricular assist device (VAD), or "artificial ventricle," is an internally implanted pump designed to aid a person with a failing left ventricle; unlike an artificial heart, it does not require removal of the patient's heart. A version for temporary use was developed in 1964. In 1991 doctors implanted the first portable VAD; it was powered by a battery pack. Its pump used a special interior lining to promote the growth of a surface similar to that which lines the blood vessels, reducing the risk of the formation of blood clots, which can cause stroke.
artificial heart:see heart, artificialheart, artificial,
external or surgically implanted mechanical device designed to replace a patient's diseased heart. The first one used on a human being, the Jarvik-7, was implanted (1982) in Barney Clark, who lived for 112 days; another patient, William Schroeder, lived 620
..... Click the link for more information. .