Heart transplantation is reserved for people who have severe heart failure and who cannot be treated effectively with drugs or other forms of surgery. In some medical centers, heart machines can keep people alive for weeks or months until a compatible heart can be found. Also, newly developed, implantable artificial hearts are being used to tide people over until a heart is available or, in some experimental situations, to be used as a long-term replacement. Nonetheless, many people die while waiting.

About 95% of people who have had a heart transplant are substantially better able to exercise and carry out daily activities than they were before the transplantation. About 85% of heart transplant recipients survive for at least 1 year.

Through an incision in the chest, most of the damaged heart is removed, but the back walls of the upper heart chambers (atria) are left. The donated heart is then attached to what remains of the recipient's heart. The procedure takes about 3 to 5 hours. The hospital stay after this operation is usually 7 to 14 days.

Immunosuppressants must be taken to prevent rejection of a transplanted heart. Rejection, if it occurs, usually causes fever, weakness, and a rapid or other abnormal heart rhythm. With rejection, the transplanted heart may not function well, causing low blood pressure and fluid accumulation in the legs and sometimes the abdomen, resulting in swelling—a condition called edema. Fluid may also accumulate in the lungs. If rejection is mild, no symptoms may occur, but electrocardiography (ECG) may detect changes in the heart's electrical activity.

If doctors suspect rejection, they usually do a biopsy. A catheter is inserted through an incision in the neck into a vein and is threaded to the heart. A device at the end of the catheter is used to remove a small piece of heart tissue, which is examined under a microscope. Doctors also routinely do biopsies once a year to look for rejection that has not yet caused symptoms.

Nearly half of all deaths that occur after heart transplantation are due to infections. About one fourth of people who have a heart transplant develop atherosclerosis in the coronary arteries.

Last full review/revision September 2008 by Martin Hertl, MD, PhD; James F. Markmann, MD, PhD; Paul S. Russell, MD; Heidi Yeh, MD