About 4,000 people in the United States await heart transplants each year. During a typical year, only about 2,500 donor hearts become available.
Some of the 4,000 people awaiting heart transplants have nonreversible biventricular failure, a condition in which both the left and right sides of the heart are not functioning properly. These people could be candidates for an artificial heart.
Many types of artificial hearts are now being tested. In general, they are composed of two main parts. There is a smaller mechanical part that is connected to the per-son’s heart or major arteries. It receives the blood and pumps it out of the mechanical heart into the aorta, the body’s biggest artery. This internal part is connected to an air pump by hoses that exit the chest.
Currently, the air pump is a washing machine–sized console that pro-vides the power to the artificial heart. Manufacturers are working on smaller external pumps that can make the patient more mobile.
Although these devices help many patients successfully wait for a heart transplant, they are not without problems. In one study, 72 percent of those in the study developed infection. Other complications from artificial hearts include bleeding in the chest and lungs, strokes, and device malfunctions. Though researchers have been working on artificial hearts that could permanently replace diseased hearts, there are no such devices approved for permanent use.
The artificial heart is like a safety net for some patients, making them a better candidate for transplantation.
The goal is to improve blood function, as well as lung and kidney function. They are intended as a temporary aid for patients with severe heart failure, unresponsive to maximal medical therapy, who are not expected to live longer than 30 days.