Thursday, March 23, 2006

ARTIFICIAL-HEART PATIENT DIES:

:
March 23, 1983

On March 23, 1983, Barney Clark dies 112 days after becoming the world's first
recipient of a permanent artificial heart. The 61-year-old dentist spent the
last four months of his life in a hospital bed at the University of Utah Medical
Center in Salt Lake City, attached to a 350-pound console that pumped air in and
out of the aluminum-and-plastic implant through a system of hoses.In the late
19th century, scientists began developing a pump to temporarily supplant heart
action. In 1953, an artificial heart-lung machine was employed successfully for
the first time during an operation on a human patient. In this procedure, which
is still used today, the machine temporarily takes over heart and lung function,
allowing doctors to operate extensively on these organs. After a few hours,
however, blood becomes damaged by the pumping and oxygenation.In the late 1960s,
hope was given to patients with irreparably damaged hearts when heart-transplant
operations began. However, the demand for donor hearts always exceeded
availability, and thousands died every year while waiting for healthy hearts to
become available.On April 4, 1969, a historic operation was performed by surgeon
Denton Cooley of the Texas Heart Institute on Haskell Karp, a patient whose
heart was on the brink of total collapse and to whom no donor heart had become
available. Karp was the first person in history to have his diseased heart
replaced by an artificial heart. The temporary plastic-and-Dacron heart extended
Karp's life for the three days it took doctors to find him a donor heart.
However, soon after the human heart was transplanted into his chest, he died
from infection. Seven more failed attempts were made, and many doctors lost
faith in the possibility of replacing the human heart with a prosthetic
substitute.In the early 1980s, however, a pioneering new scientist resumed
efforts to develop a viable artificial heart. Robert K. Jarvik had decided to
study medicine and engineering after his father died of heart disease. By 1982,
he was conducting animal trials at the University of Utah with his Jarvik-7
artificial heart.On December 2, 1982, a team led by Dr. William C. DeVries
implanted the Jarvik-7 into Barney Clark. Because Jarvik's artificial heart was
intended to be permanent, the Clark case drew worldwide attention. Clark spent
his last 112 days in the hospital and suffered considerably from complications
and the discomfort of having compressed air pumped in and out of his body. He
died on March 23, 1983, from various complications. Clark's experience left many
feeling that the time of the permanent artificial heart had not yet come.During
the next decade, Jarvik and others concentrated their efforts on developing
mechanical pumps to assist a diseased heart rather than replace it. These
devices allow many patients to live the months or even years it takes for them
to find a donor heart. Battery powered, these implants give heart-disease
patients mobility and allow them to live relatively normal lives. Meanwhile, in
the 1990s, the Jarvik-7 was used on more than 150 patients whose hearts were too
damaged to be aided by the mechanical pump implant. More than half of these
patients survived until they got a transplant.Today, Jarvik and others are
working to develop smaller and more efficient mechanical pump implants. A
company called ABIOMED has developed a new permanent artificial heart. This
"total replacement" device, which is awaiting FDA approval, is powered by an
internal battery and does not require air pumps, thus promising unprecedented
mobility to recipients.

No comments: