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Definition
Ebstein's anomaly is a rare heart defect that's present at birth (congenital). It primarily involves the lower right chamber of your heart (right ventricle) and the tricuspid valve — the valve between the upper right chamber (atrium) and the right ventricle.
In Ebstein's anomaly, your tricuspid valve doesn't work properly, so blood leaks back through the valve and into the right atrium. As a result, your heart works less efficiently. Ebstein's anomaly may also lead to enlargement of the heart. In addition, about half the people with Ebstein's anomaly have a hole in their heart, and one in four has episodes of fast heartbeats.
If no signs or symptoms are present, careful monitoring of your heart may be all that's necessary. If signs and symptoms become troublesome, or if the heart is enlarging or becoming weaker, treatment for Ebstein's anomaly may be necessary. Treatment options include medications and surgical repair.
Symptoms
People with a mild form of Ebstein's anomaly may not experience any signs or symptoms until later in adulthood. Even some people with very abnormal valves may have minimal, if any, problems. Signs and symptoms may develop slowly over many years and include:
- Shortness of breath
- Fatigue, especially with exertion
- Leg swelling
- Heart palpitations or abnormal heart rhythms (arrhythmias)
- A bluish discoloration of the lips and skin caused by low oxygen (cyanosis)
Newborns and infants who are diagnosed with Ebstein's anomaly usually show signs of cyanosis early, in addition to signs and symptoms of heart failure. When signs and symptoms are apparent at such a young age, this usually indicates a severe defect that requires intensive care.
Older children may show signs of heart failure, such as tiring easily or becoming short of breath during play. They may also experience sensations of the heart pounding or racing or show signs of cyanosis, especially around the lips and fingertips.
Causes
Your heart is made up of four chambers. The top two chambers are the right and left atria (plural for atrium). The two lower chambers, the ventricles, are larger, thick-walled chambers that do the work of pumping blood. Separating the atria from the ventricles are flexible structures called valves, which keep the blood flowing in the right direction through the heart. Each valve consists of two or three strong, thin flaps (leaflets) of tissue. When closed, a valve prevents blood from flowing to the next chamber or from returning to the previous chamber.
Deoxygenated blood returning from your body flows into the right atrium, through the tricuspid valve and then into the right ventricle, which pumps the blood to your lungs to receive oxygen. On the other side of your heart, freshly oxygenated blood from your lungs flows into the left atrium, through the mitral valve and then into the left ventricle, which pumps the blood to the rest of your body.
What happens in Ebstein's anomaly
In Ebstein's anomaly, the tricuspid valve is displaced downward into the right ventricle so that a portion of the right ventricle becomes part of the right atrium (becomes atrialized). As a result, the right atrium is larger than usual and the functional right ventricle is abnormal.
In addition to the downward displacement of the tricuspid valve, the valve's leaflets are typically malformed. This can lead to blood leaking backward (regurgitating) into the right atrium. In cases of severe malformation, the leaflets may be tethered to the wall of the right heart, inhibiting their movement and leading to severe leakage of blood into the atrium. One leaflet — the anterior leaflet — is often enlarged (sometimes described as "sail-like") in contrast to the other two small leaflets.
The degree of downward displacement and malformation varies from person to person. In some, the valve is only mildly abnormal. In others, the valve may be extremely displaced and malformed, and there may be severe leakage. With greater leakage of the valve, the right atrium enlarges as it receives an increased volume of blood. At the same time, the right ventricle enlarges (dilates) as it tries to cope with the leaky valve and still propel blood to the lungs. Thus, the right-sided chambers of the heart enlarge, and as they do so, they weaken, leading to right heart failure.
Congenital heart defects arise early in the development of a baby's heart. What causes the defect to occur is uncertain. Genetic and environmental factors are both thought to play a role. In rare cases, a mother's exposure to lithium or a viral infection may lead to Ebstein's anomaly.
Associated disorders
Other heart disorders may be associated with Ebstein's anomaly. Two common conditions are:
- Atrial septal defect. About half the people with Ebstein's anomaly have a hole between the two upper chambers of the heart called an atrial septal defect. This hole may allow deoxygenated blood in the right atrium to mix with oxygenated blood in the left atrium, decreasing the amount of oxygen available in your blood and causing cyanosis. Depending on the size of the hole, an atrial septal defect associated with Ebstein's anomaly can increase your risk of a blood clot passing from your peripheral veins — which return deoxygenated blood to your heart — into your general circulation and causing a stroke. If you have surgery to repair your tricuspid valve, your surgeon will also close the atrial septal defect at the same time.
- Heart rhythm disturbances (arrhythmias). In a normal heart, a special group of cells in the right atrium generates electrical impulses that travel via specific pathways through the heart. These electrical impulses help your heart to beat in an orderly and efficient manner. But about 15 percent of people with Ebstein's anomaly have one or more extraneous (accessory) pathways that allow electrical impulses to bypass the normal circuit and cause an abnormal heart rhythm (arrhythmia) characterized by rapid heartbeats (tachycardia). These types of arrhythmias (tachyarrhythmias) can reduce your heart performance, especially when the tricuspid valve is leaking severely. In addition, other tachyarrhythmias, such as atrial fibrillation and atrial flutter, occur with increased frequency as the right atrium becomes dilated. In some cases, a very fast heart rhythm may cause fainting spells (syncope).
When to seek medical advice
If you or your child is experiencing signs or symptoms of heart failure — such as feeling easily fatigued or short of breath, even with normal activity — or is showing blue skin coloration around the lips and nails (cyanosis), talk to your doctor. He or she may refer you to a doctor who specializes in heart disease (cardiologist).
Tests and diagnosis
If you don't have any signs or symptoms that may indicate a heart defect, the first clue may be the presence of an abnormal heart sound or heart murmur discovered during a regular checkup, even though most people with a heart murmur don't have any heart defects. A doctor uses a stethoscope to listen to your heart and evaluate the quality, frequency and duration of any abnormal sounds.
If your doctor suspects an underlying problem, such as congenital heart disease, or if you have other signs and symptoms that may suggest Ebstein's anomaly, your doctor may recommend the following tests:
- Chest X-ray. A chest X-ray shows a picture of your heart, lungs and blood vessels. It can reveal if your heart is enlarged, which may increase suspicion of Ebstein's anomaly.
- Echocardiogram. This exam uses ultrasound waves to show detailed images of your heart's structure and function. It can detect most congenital heart defects. Ultrasound waves are transmitted, and their echoes are recorded with a device called a transducer that's held outside your body. A computer uses the information from the transducer to create moving images on a video monitor. This test can identify the degree of valve displacement, the severity of leakage from the valve, the size of your heart chambers, whether an opening exists between the two upper chambers, and whether there are any other associated defects.
- Electrocardiogram (ECG). An ECG uses sensors (electrodes) attached to your chest and limbs to measure the timing and duration of each electrical phase in your heartbeat. An ECG can help your doctor detect irregularities in your heart's rhythm and structure, and offer clues as to the presence of an extra pathway.
- Holter monitor testing. This is a portable version of an ECG. It's especially useful in diagnosing rhythm disturbances that occur at unpredictable times. You wear the monitor under your clothing. It records information about the electrical activity of your heart as you go about your normal activities for a day or two.
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Cardiac catheterization. Doctors rarely use this more invasive technique for Ebstein's anomaly because other less invasive techniques, such as an echocardiogram, provide the needed information for diagnosis. In a few cases, however, a person may need cardiac catheterization to obtain additional information, to confirm findings from other tests, or to check heart arteries.
During cardiac catheterization, a slender, flexible tube (catheter) is inserted into a vein or artery at the top of your leg (groin) or into your arm. Aided by X-ray images on a monitor, your doctor threads the catheter through that artery until it reaches your heart. A special dye injected through the catheter helps your doctor see the blood flow through your heart, blood vessels and valves, and allows your doctor to check for abnormalities and obtain pressure measurements inside the heart and lungs.
Complications
Many people with mild Ebstein's anomaly live relatively free of complications. Certain situations may call for some precautions, however, depending on the severity of your condition.
For example, people with Ebstein's anomaly are at an increased risk of endocarditis, an infection of the membrane that lines the interior of the heart chambers and valves. To prevent such an infection, your doctor may prescribe antibiotics before certain dental and surgical procedures.
Other complications that may result from Ebstein's anomaly include heart failure, rhythm problems and, less commonly, sudden cardiac arrest or stroke.
Physical activity
If you have mild Ebstein's anomaly with a nearly normal heart size and no heart rhythm disturbances, you can probably participate in most physical activities. Depending on your signs and symptoms, your doctor may recommend that you avoid competitive sports, such as football or basketball. Your cardiologist can help you decide which activities are right for you.
Pregnancy
In most cases, women with mild Ebstein's anomaly can carry a child to term and have a safe delivery. But pregnancy does have its risks. Being pregnant puts additional strain on your heart and circulation system not only during pregnancy, but also during labor and delivery and for a period of time after your baby's birth. There is an increased risk of stroke if you have a hole between the upper chambers of the heart (atrial septal defect).
Some women with Ebstein's anomaly develop severe complications and even death during pregnancy. If you plan on becoming pregnant, be sure to talk to your cardiologist ahead of time. He or she can assess the safety of pregnancy in your case and help determine how much extra monitoring you may need throughout pregnancy and childbirth.
Treatments and drugs
Treatment of Ebstein's anomaly depends on the severity of the defect and your signs and symptoms. The goal of treatment is to minimize symptoms and avoid future complications, such as progressive heart enlargement and heart failure, and arrhythmias. Treatment strategies may include:
Regular monitoring
If you have no signs or symptoms or abnormal heart rhythms, your doctor may simply recommend careful monitoring of your heart condition with regular checkups. Checkups typically include a thorough physical exam, electrocardiogram, chest X-ray, echocardiogram and, if necessary, a Holter monitor test. Your doctor may also ask you to undergo an exercise test, such as walking on a treadmill. This test measures your tolerance for activity and checks your heart's response to exertion (exercise).
Medications
If you have heart rhythm disturbances, medications may help control heart rate and maintain normal heart rhythm. Doctors commonly use medications, including calcium channel blockers, beta blockers, digitalis and anti-arrhythmic drugs, such as amiodarone.
Your doctor may also prescribe medications for signs and symptoms of heart failure, if you need them. These may include diuretics and digoxin. The role of angiotensin-converting enzyme (ACE) inhibitors and beta blockers, medications commonly used to treat other forms of heart failure, isn't well established in people with Ebstein's anomaly who have heart failure.
Surgical heart repair
Your doctor may recommend surgical repair when your signs and symptoms are troublesome or when your heart begins to enlarge and overall heart function begins to decrease. Because Ebstein's anomaly is rare, choose a surgeon who's familiar with the defect and who has experience performing the procedure. Different types of procedures can be used to surgically treat Ebstein's anomaly and associated defects, including:
- Tricuspid valve repair. This involves reducing the size of the valve opening and allowing the existing valve leaflets to come together in order to create a better functioning valve. This procedure is usually done when there's enough valve tissue to allow for repair. An experienced surgeon is more likely to perform a successful valve repair.
- Tricuspid valve replacement. If the existing valve can't be repaired, it may be replaced by removing the deformed valve and inserting either a mechanical valve or a specially treated biological tissue (bioprosthetic) valve. If a mechanical valve is used, you'll need to take a blood-thinning medication for the rest of your life. The durability of a bioprosthetic valve is favorable in this location. Consequently, a bioprosthetic valve is preferred in most circumstances when replacement is necessary.
- Closure of the atrial septal defect. If an atrial septal defect is present, your surgeon can close the channel during surgery to repair or replace the defective valve.
- Maze procedure. Another procedure that doctors may perform during valve repair or replacement surgery is called a maze procedure. It's used to address abnormally fast heart rhythms in the atrium (atrial tachyarrhythmias). To do the procedure, your surgeon makes a series of incisions in the right atrium with a scalpel or a cryoablation device that destroys tissue by freezing it. When these incisions heal, the scars they leave interrupt the extra electrical pathways and act as boundaries to force orderly electrical activation.
Radiofrequency catheter ablation
Some extraneous electrical pathways also can be treated using catheter ablation. In this procedure, one or more catheters are threaded through your blood vessels to your inner heart. They're positioned along electrical pathways identified by your doctor as causing your arrhythmia. Electrodes at the catheter tips are heated with radiofrequency energy. This destroys (ablates) a small spot of heart tissue and creates an electrical block along the pathway that's causing your arrhythmia. Usually, this stops your arrhythmia.
Heart transplantation
If you have Ebstein's anomaly with severe valve involvement and markedly reduced heart function, you may be eligible for heart transplantation.
Coping and support
If you or your child has mild Ebstein's anomaly, here are some steps that may help you cope:
- Follow up on medical care. Be sure to follow up with your cardiologist or pediatrician for regular evaluations. Be an active participant in monitoring the condition and report any new or worsening signs or symptoms. Timely treatment can keep the condition from becoming worse.
- Take medications as prescribed. Taking medications at the right dose and the right time can help to minimize the impact of symptoms such as racing heartbeats, fatigue and shortness of breath. Tell your doctor about any upcoming dental work or surgery so that he or she can prescribe antibiotics in advance, to prevent infection of the heart's lining (endocarditis).
- Stay active. Engage in as much physical activity as your doctor allows. Exercise can help strengthen your heart and improve your blood circulation. As a parent of a child with Ebstein's anomaly, it's natural to want to protect your child from harm. But remember that your child needs to live life as normally as possible. Encourage playtime with breaks as needed. Ask your doctor for a note you can give to your child's teachers or caregivers describing any restrictions on his or her physical activity.
- Develop a support network. Although many people with congenital heart defects lead normal, healthy lives, living with a heart defect isn't always easy, particularly when you or your child needs continued specialized care. The physical, emotional and financial stress of coping with a serious health condition can be overwhelming. Having family and friends you can rely on is critical to successful coping. In addition, you may wish to ask your doctor about local support groups that may be helpful. Support groups can be a great source of practical information, comfort and friendship.
Last Updated: 11/01/2006
