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Endocardial Cushion Defect (Atrioventricular Septal Defect)

What is an endocardial cushion defect?

Endocardial cushion defect is a birth defect of the heart. It is also called atrioventricular canal defect (AVCD). AVCD involves problems with the structure of the heart. The heart normally has 2 upper chambers (atria) and 2 lower chambers (ventricles). A normal heart has 2 heart valves that separate the upper and lower chambers (the tricuspid and mitral valves).

In AVCD, there may be a large hole in the wall between the chambers of the heart (the atrioventricular septum). In some cases the tricuspid and mitral valves may not be separate. Instead, there can be one large valve between the upper and lower chambers of the heart (called the common atrioventricular valve).

The large opening in the center of the heart allows oxygen-rich and oxygen-poor blood to mix. The heart pumps blood in a way that is not efficient. The heart has to work harder and it gets enlarged.

What is the cause?

AVCD can happen when the heart does not develop normally before birth. The exact cause is not known, but it is commonly found in babies with Down syndrome.

What are the symptoms?

The symptoms may start at any time from birth to several months after birth. Most babies with this problem do not eat well. They may not grow normally. They breathe fast. They often have colds and may get pneumonia. They may sweat and be clammy.

How is it diagnosed?

Children with AVCD usually have a heart murmur, which a healthcare provider can hear with a stethoscope. A heart murmur is an extra sound made between heartbeats. The murmur is caused by the abnormal flow of blood through the heart.

Tests may include:

  • A chest X-ray to look for enlargement of the heart
  • An ECG (also called an EKG or electrocardiogram), which measures and records your child’s heartbeat
  • An echocardiogram, which uses sound waves (ultrasound) to see how well your child’s heart is pumping
  • Heart catheterization, which uses a small tube called a catheter inserted into a blood vessel and into the heart. Dye is injected into a vein and X-rays are taken of the heart.

How is it treated?

Surgery is needed to repair the defect. First, medicines may be given to help your baby feel better and get strong enough to have surgery. When your child has surgery, your healthcare provider will close the hole in the septum and rebuild the valves if necessary.

In rare cases, the defect is too complex to make all of the repairs at one time. Your child’s healthcare provider may put a band around the lung artery to narrow the artery and reduce blood flow to the lungs. Then the heart will not have to work as hard, and the lungs will be protected from high blood pressure. When your child is older, the pulmonary artery band can be removed and corrective surgery done.

If a child with AVCD is not treated, they may:

  • Often have pneumonia
  • Have an enlarged heart, which means the heart won’t pump as well as it should
  • Have high blood pressure in the lungs
  • Have heart failure, which means the heart is not pumping as well as it should

With treatment, your child has a much better chance for a healthier life. Your child will need to have regular follow-up visits with a heart specialist to check for any new problems.

How can I take care of my child?

Follow your child’s healthcare provider's instructions. Ask your provider:

  • How and when you will hear your child’s test results
  • How long it will take for your child to recover
  • What activities your child should avoid and when your child can return to normal activities
  • How to take care of your child at home
  • If your child should take antibiotics to prevent infection before having dental work or procedures that involve the rectum, bladder, or vagina
  • What symptoms or problems you should watch for and what to do if your child has them

Make sure you know when your child should come back for a checkup.

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Published by RelayHealth.
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