Left Ventricular Assist Devices

The totally artificial heart, which received much publicity in the 1970s and 1980s, was conceptually flawed. These unwieldy devices were acceptable as a bridge to transplantation (when meant to keep patients alive until they could receive a heart transplant) but were never a long-term solution. To be successful, an artificial heart must be more than a reliable blood pump; it must be forgettable. That was something the big artificial hearts could never be.

In recent years, however, physicians have realized that whole-heart replacement may not be necessary. After all, more than 90 percent of heart failure patients can be sustained with left ventricular support alone.

Currently, left ventricular assist devices are used mainly as a bridge to transplantation. The modern left ventricular assist device consists of a blood sac that is compressed by a pusherplate mechanism that is either electrically or air driven. Artificial heart valves direct the blood flow. This system mimics the human left ventricle by providing pulsatile blood flow while taking the burden of pumping off the patient's heart. This is a workable solu tion and saves many lives, but the serious problems of pump size, noise, driveline infection, and stroke remain. Nevertheless, some patients have had these devices in place for up to four years and enjoyed an acceptable quality of life. This has encouraged us to use the left ventricular assist device for long-term support in patients who are not eligible for transplantation.

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