Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Heart Transplantation


Martin Hertl

, MD, PhD, Rush University Medical Center

Reviewed/Revised Aug 2022 | Modified Sep 2022
Topic Resources

Heart transplantation is the removal of a healthy heart from a recently deceased person and then its transfer into the body of a person who has a severe heart disorder that can no longer be treated effectively with drugs or other types of surgery.

Heart Biology of the Heart The heart and blood vessels constitute the cardiovascular (circulatory) system. The heart pumps the blood to the lungs so it can pick up oxygen and then pumps oxygen-rich blood to the body.... read more transplantation is reserved for people who have one of the following disorders if the disorder 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, implantable artificial hearts (called ventricular assist devices or VADs) that pump blood to the rest of the body are being used to tide people over until a heart is available or are used in people who are not candidates for heart transplantation. These devices are increasingly being used as a long-term replacement. As a result, the need for heart transplantation has somewhat decreased.

Left Ventricular Assist Device

About 95% of people who have had a heart transplant are substantially better able to exercise and do daily activities than they were before the transplantation. Over 70% return to full-time employment. About 85 to 90% of heart transplant recipients survive for at least 1 year.


All donated hearts come from someone who has recently died. Donors must be under 60 years old and have not had coronary artery disease or other heart disorders. Also, the blood type and heart size of the donor and recipient must match.

Donated hearts must be transplanted within 4 to 6 hours.

Procedure for Heart Transplantation

Through an incision in the chest, most of the damaged heart is removed, but the back wall of one of the upper heart chambers (atria) is left. The donated heart is then attached to what remains of the recipient’s heart.

Heart transplantation takes about 3 to 5 hours. The hospital stay after this operation is usually 7 to 14 days.

Drugs to inhibit the immune system (immunosuppressants Suppression of the Immune System Transplantation is the removal of living, functioning cells, tissues, or organs from the body and then their transfer back into the same body or into a different body. The most common type of... read more ), including corticosteroids, are started the day of transplantation. These drugs can help reduce the risk that the recipient will reject the transplanted heart.

Complications of Heart Transplantation

Most deaths that occur after heart transplantation are due to rejection soon after the operation or to infections.


Even if tissue types are closely matched, transplanted organs, unlike transfused blood, are usually rejected unless measures are taken to prevent rejection. Rejection results from an attack by the recipient's immune system on the transplanted organ, which the immune system recognizes as foreign material. Rejection can be mild and easily controlled or severe, resulting in destruction of the transplanted organ.

Immunosuppressants are drugs that block or slow the immune system and must be taken to prevent rejection of a transplanted heart.

Rejection, if it occurs, may cause weakness and a rapid or other abnormal heart rhythm. When rejection occurs, the transplanted heart may not function well, causing low blood pressure and accumulation of fluid in the legs and sometimes the abdomen, resulting in swelling—a condition called edema. Fluid may also accumulate in the lungs, causing difficulty breathing. However, rejection is often mild. In such cases, 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. Because effects of rejection can be serious, doctors also routinely do a biopsy once a year to look for rejection that has not yet caused symptoms.

Transplant-related atherosclerosis

Drugs Mentioned In This Article

Generic Name Select Brand Names
Cardizem, Cardizem CD, Cardizem LA, Cardizem SR, Cartia XT , Dilacor XR, Dilt-CD , Diltia XT, Diltzac, Matzim LA, Taztia XT, TIADYLT ER, Tiamate, Tiazac
quiz link

Test your knowledge

Take a Quiz!