The left ventricular assist device, or LVAD, is a mechanical pump that is implanted inside a person's chest to help a weakened heart ventricle pump blood throughout the body.
Unlike a total artificial heart, the LVAD doesn't replace the heart. It just helps it do its job. This can mean the difference between life and death for a person whose heart needs a rest after open-heart surgery, or for some patients waiting for a heart transplant (called "bridge to transplant").
LVADs may also be used as destination therapy, which is an alternative to transplant. Destination therapy is used for long-term support in some terminally ill patients whose condition makes them ineligible for heart transplantation.
The device, consists of an electric motor and a driveline. A connection to the left ventricle diverts blood from the heart to the pump. The motion of the pump then propels the blood back into the aorta—with enough force to be distributed adequately throughout the body.
The pumps used in LVADs can be divided into two main categories: pulsatile and continuous-flow.
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In addition to extending the life of the patient's own heart, the improved blood flow to the body allows patients to breathe easier and experience less fatigue. Since the LVAD system is relatively easy to use, patients can leave the hospital setting with the implanted device and return to the activities of normal life.
A Little VAD History
The first successful long-term implantation of an artificial LVAD was conducted in 1988 by Dr. William F. Bernhard of Children's Hospital Medical Center.
The early VADs emulated the heart by using a "pulsatile" action where blood is alternately sucked into the pump from the left ventricle then forced out into the aorta.
More recent work has concentrated on continuous flow pumps, which can be roughly categorized as either centrifugal pumps or axial flow impeller driven pumps.
Peter Houghton was the longest surviving recipient of a VAD for permanent use. He received an experimental Jarvik 2000 LVAD in June 2000. Since then, he completed a 91-mile charity walk, published two books, lectured widely, hiked in the Swiss Alps and the American West, flew in an ultra-light aircraft, and traveled extensively around the world. He died of acute renal failure in 2007 at the age of 69.
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