Organ Rejection

Organ rejection is a very specific problem that can occur after transplantation.

Because a new heart comes from another person, your child's immune system will recognize that the heart is different and may try to attack it. If your child's immune system injures the heart, this is called rejection.

Rejection does not necessarily mean that your child will lose the heart. If detected early, most rejection episodes can be treated successfully.

The Three Types of Heart Transplant Rejection


Hyperacute rejection occurs right after the blood supply is connected to the new heart during surgery. This is a complication caused by certain antibodies in the blood that reject the new heart.

This type of rejection is rare because we test for these antibodies early in process of transplant evaluation. This test is known as panel of reactive antibodies (PRA) testing.


Acute rejection usually occurs within the first six months after transplant. It is common to see at least one rejection episode about two to three months after surgery.

This is why we check your child so closely with lab work and other tests. If rejection is diagnosed, we can usually treat it successfully with medication.


Chronic rejection occurs slowly over time. It can be more difficult to reverse. Our care is focused on maintaining heart function for as long as possible. Your child may not require another transplant for years.

The possibility for rejection is greatest soon after transplant. But at any point your child's immune system may try to attack the heart.

For the new heart to live successfully in your child's body, we must give your child medicines that suppress the immune response. Your child will need to take medicines exactly as instructed.

We will frequently draw blood to check the level of immunosuppression medications in your child's system, since these are essential for your child's survival. We will also monitor your child with regular echocardiographic studies, a painless way to look at the heart and its function using sound waves.

We will also biopsy your child's new heart to check it for any signs of rejection. A biopsy is a procedure where a catheter is put in through your child's leg and up into the heart to take a small sample of tissue. This tissue is then looked at under a microscope to see if there has been any injury to the cells of the heart. Your child will be asleep for this procedure. This procedure is done in day surgery and you can typically take your child home the same day. Learn more about cardiac catheterization procedures.

The most common rejection symptoms include:

  • Fever
  • Decreased urine output or fewer wet diapers than usual
  • Elevated heart rate
  • Fast breathing rate
  • Weight gain
  • Fatigue
  • Irritability
  • Poor appetite

Every child is different and some or none of these symptoms may occur during a rejection episode. This is why we must check your child often with lab and physical tests.

Your child's transplant team will instruct you on whom to call right away if any of these symptoms occur.

Not Following Instructions (Non-Adherence)

When a patient or family is not following the transplant team's instructions, we use the term non-adherence. This can mean not taking medications properly, not getting blood draws on time or not getting the medical follow-up that is needed.

Some transplants fail because of non-adherence on the part of patients and families.  

Remembering to take medications is very important. At the time of transplantation, your child will receive medicines to suppress the immune system. The type or combination of medicines depends on many factors.

You and your child must be committed to taking the prescribed doses of these medicines on a strict daily schedule. Not following all medical instructions can result in heart failure for your child.

While it is important that your child learn responsibility for taking their own medications, children and teens will often forget or delay doing the things that they need to do.

You must supervise your child's medication schedule for the sake of your child's heart and overall health.