Heterotrophic heart transplant (a.k.a Double heart transplant) is a surgical procedure that was first developed in the 1970’s, where the donor’s heart is transplanted without removing the recipient’s original heart
Heterotrophic heart transplantation was first performed on humans in 1974. What makes it different from the traditional heart transplantation is the fact that the patient's original heart is not removed. During surgery, the donor's heart is connected to the recipient's blood vessels, thus connecting both heart chambers to the same system, creating the situation of a "double heart". The donor's heart is placed in the right side of the chest, next to the original heart.
This procedure is used when the recipient's body is too large for the donor's heart, or when the patient has pulmonary high blood pressure (that is, high blood pressure in the vessels that transport blood from the heart to the lungs).
The advantage of this is that the procedure can give the patient's original heart time to recover, and even if the donor's heart fails, the original heart can continue beating. However, complications like organ rejection, infection and side effects of immunosuppressive medications can still occur.