Ebstein anomaly

Overview

Ebstein anomaly is a rare heart defect that's present at birth (congenital). In this condition, your tricuspid valve is in the wrong position and the valve's flaps (leaflets) are malformed. As a result, the valve does not work properly.

Blood might leak back through the valve, making your heart work less efficiently. Ebstein anomaly can also lead to enlargement of the heart and heart failure.

If you have no signs or symptoms associated with Ebstein anomaly, regular monitoring of your heart might be all you need. You might need treatment if signs and symptoms bother you or if your heart is enlarging or weakening. Treatment options include medications and surgery.

Symptoms

Mild forms of Ebstein anomaly might not cause symptoms until later in adulthood. Signs and symptoms might include:

• Shortness of breath, especially with exertion
• Fatigue
• Heart palpitations or abnormal heart rhythms (arrhythmias)
• A bluish discoloration of the lips and skin caused by low oxygen (cyanosis)

When to see a doctor

If you or your child has signs or symptoms of heart failure — such as feeling easily fatigued or short of breath, even with normal activity — or if the skin around the lips and nails looks blue or you have swelling of your legs, talk to your doctor. He or she may refer you to a doctor who specializes in congenital heart disease (cardiologist).

Causes

Ebstein anomaly is a heart defect that you have at birth (congenital). The cause is unknown. To understand how Ebstein anomaly affects your heart, it helps to know how the heart works to supply your body with blood.

How your heart works

Your heart is made up of four chambers. The two upper chambers (atria) receive blood. The two lower chambers (ventricles) pump blood.

Four valves open and close to let blood flow in one direction through the heart. Each valve consists of two or three strong, thin flaps (leaflets) of tissue. A closed valve prevents blood from flowing to the next chamber or from returning to the previous chamber.

Oxygen-poor blood from your body flows into the right atrium. Blood then flows through the tricuspid valve into the right ventricle, which pumps the blood to your lungs. On the other side of your heart, oxygen-rich blood from your lungs flows into the left atrium, through the mitral valve and into the left ventricle, which then pumps the blood to the rest of your body.

What happens in Ebstein anomaly

The tricuspid valve normally sits between the two right heart chambers (right atrium and right ventricle).

In Ebstein anomaly, the tricuspid valve sits lower than normal in the right ventricle. This makes it so that a portion of the right ventricle becomes part of the right atrium, causing the right atrium to enlarge and not work properly.

Also, the tricuspid valve's leaflets are abnormally formed. This can lead to blood leaking backward into the right atrium (tricuspid valve regurgitation).

The location of the valve and how poorly it's formed varies from person to person. Some people have a mildly abnormal valve. Others have a valve that leaks severely.

Other heart conditions associated with Ebstein anomaly

Common associated heart conditions include:

• Holes in the heart. Many people with Ebstein anomaly have a hole between the two upper chambers of the heart called an atrial septal defect or an opening called a patent foramen ovale (PFO). A PFO is a hole between the upper heart chambers that all babies have before birth that usually closes after birth. It can remain open in some people without causing issues.

  These holes can decrease the amount of oxygen available in your blood, causing a bluish discoloration of the lips and skin (cyanosis).

• Abnormal heartbeats (arrhythmias). An abnormal heart rhythm or rapid heartbeats make it difficult for the heart to work properly, especially when the tricuspid valve is leaking severely. Sometimes, a very fast heart rhythm causes fainting spells (syncope).
• Wolff-Parkinson-White (WPW) syndrome. People with WPW syndrome have an abnormal electrical pathway in the heart that can lead to fast heart rates and fainting spells.

Risk factors

Congenital heart defects, such as Ebstein anomaly, occur as the baby's heart develops in the mother's womb.

Doctors aren't sure what risk factors are associated with the defect. Genetic and environmental factors are believed to play a role. A family history of heart defects or a mother's use of certain medications, such as lithium, during pregnancy might increase the risk of Ebstein anomaly in the child.

Complications

Mild Ebstein anomaly may not cause any complications.

However, possible complications of Ebstein anomaly include:

• Heart failure
• Sudden cardiac arrest
• Stroke

Taking a few precautions before playing sports or becoming pregnant may help prevent complications.

If your heart size is nearly normal and you have no heart rhythm disturbances, you can probably participate in most physical activities. Depending on your signs and symptoms, your doctor might recommend that you avoid certain competitive sports, such as football or basketball.

If you're planning on having a baby, talk to your doctor. Many women with mild Ebstein anomaly can safely have children. But pregnancy, labor and delivery put additional strain on your heart. Rarely, severe complications can develop that can cause death to mother or baby.

Together, you and your doctor can decide how much monitoring you need throughout pregnancy and childbirth. Sometimes, other treatments for your condition or symptoms may be recommended before you become pregnant.