Ebstein’s Abnormality: Definition, Related Conditions, Causes, Symptoms, Diagnosis, Treatment and Prognosis

This heart defect can cause oxygen-poor blood to travel to the left side of the heart through a hole in the two upper chambers and be pumped into the body.

Ebstein’s Anomaly is a rare congenital heart defect that occurs when the tricuspid valve (the valve between the right atrium and the right ventricle) of the heart does not form properly and is lower in the right ventricle than normal.

In addition to being too low, the tricuspid valve may not be formed correctly.

Normally, the tricuspid valve has three fins that allow blood to flow from the right atrium to the right ventricle.

In Ebstein’s Anomaly, due to the displacement of the tricuspid valve, the size of the right ventricle decreases and the blood seeps into the right atrium instead of being pumped into the lungs.

This causes oxygen levels to be lower than normal.

Related conditions

Many patients with Ebstein’s anomaly have other cardiac problems associated with the defect, which include:

A hole between the upper right and left chambers of the heart: called permeable foramen ovale. This orifice is normal in newborn babies and usually shortly after birth.

In babies with Ebstein’s anomaly, the pressure inside the right atrium keeps the hole open, allowing the non-oxygenated blood on the right side of the heart to travel to the left side and to the body.

Wolff-Parkinson-White  syndrome : also called pre-excitation syndrome, is another congenital heart defect in which a person is born with an additional electrical pathway in the heart.

Electric impulses are sent along this path and can interrupt the carefully orchestrated rhythm of the heart, causing an abnormal or faster heartbeat than normal.

Causes

Ebstein’s anomaly occurs during fetal development for reasons that are not entirely clear. It happens in the first eight weeks of life.

The disorder may also have a genetic component, but researchers have not been able to identify which gene is responsible.

Ebstein’s anomaly and lithium

There may be a connection between the use of lithium during pregnancy and the Ebstein anomaly, although this has not been proven.

Lithium is a mood-stabilizing drug that is often used to treat mental disorders, such as bipolar disorder .

In one study, the use of lithium in the first trimester of pregnancy resulted in an additional case of heart defects, including Ebstein’s anomaly, per 100 births.

However, the researchers point out that the higher the lithium dose, the more likely a heart malformation will occur.

If the patient is pregnant or thinking about becoming pregnant, you should not take a medicine that contains lithium.

symptom

In severe cases, the symptoms of Ebstein’s anomaly will be present at the time of birth.

In other cases, the symptoms may be so mild that they are not evident until adulthood, if they ever do.

If symptoms are present, they usually include:

  • Difficulty breathing, even with little effort.
  • Bluish skin A blue tinge is seen on the lips or skin.
  • Fatigue, caused by poorly oxygenated blood.
  • Palpitations of the heart or accelerated heartbeat.
  • Lack of growth of the child.

Diagnosis

In the fetal stage

If the fetal tricuspid valve appears abnormal or leaks and the heart enlarges in a fetal ultrasound, the Ebstein anomaly can be suspected and a fetal echocardiogram will be performed for verification.

This test is safe and noninvasive, shows the structure of the fetal heart and how it is working.

The impact of the Ebstein Anomaly can vary from mild to severe.

Because of this, an expert fetal heart team should help you decide the best course of treatment possible.

Severe cases of Ebstein’s Anomaly carry an increased risk of fetal death compared to other congenital heart defects, so careful monitoring is essential.

Most babies with a mild form of Ebstein’s Anomaly can be delivered vaginally, unless there are obstetric indications for another mode of delivery.

The best thing is that the baby is born in a medical center where there is access to a team of pediatric cardiologists and neonatologists, together with a Neonatal Intensive Care Unit.

In newborns

When this anomaly is not detected in the fetal stage, once the symptoms appear, a physical examination and evaluation of these symptoms is performed.

The definitive diagnosis of Ebstein’s anomaly is usually made by imaging tests. They may include any or all of the following procedures:

  1. Chest x-ray.
  2. Echocardiogram.
  3. Electrocardiography .
  4. Cardiac magnetic resonance.

Treatment

The treatment of Ebstein’s anomaly varies according to the severity of the symptoms. For mild cases, medications may be the only treatment needed. For more severe cases, surgery may be necessary.

When treatment is needed, it usually includes:

  • Supervision: If the symptoms are mild, you may not need treatment. The doctor will want to use imaging tests to monitor your condition and make sure the symptoms do not become more severe.
  • Medications: After delivery, the baby will need prostaglandin , an intravenous drug that keeps the patent ductus arteriosus open (a normal connection present in babies in the womb). The persistent ductus arteriosus will allow blood to flow to the lungs.
  • Radiofrequency ablation for arrhythmias: older children who have arrhythmias that the medication can not control effectively and may need this procedure which is minimally invasive.
  • Surgery: When the symptoms are severe and the heart enlarges, the doctor may recommend surgery. In some cases, surgeons will try to repair the tricuspid valve. In other cases, the valve may have to be completely removed and replaced with an artificial valve or what doctors call a “bioprosthesis”.

There are some possible surgeries, depending on the nature of the heart defect such as:

Repair of the surgical valve: if possible, the surgeon repairs the structure of the tricuspid valve.

The valve replacement: if this valve can not be surgically repaired, surgeons can perform a valve replacement.

Three-stage surgical procedures: in severe cases of Ebstein’s Anomaly, the right ventricle may be too small to do the work of the right heart. In this case, three surgeries will be performed:

  • Starnes procedure: this surgery is usually done in the first week of life. The surgeon stitches the leaky tricuspid valve (the valve between the right atrium and the right ventricle) and then creates an extra connection (called a Blalock-Taussig lead) to provide blood flow to the lungs.
  • Glenn procedure : this procedure usually occurs between four and six months of age. This surgery creates a direct connection between the pulmonary artery and the superior vena cava (a vessel that returns oxygen-poor blood from the upper part of the body to the heart).
  • Fontan procedure : this procedure usually occurs between two and four years of age. This surgery connects the pulmonary artery and the inferior vena cava (a vessel that returns oxygen-poor blood from the lower part of the body to the heart), which allows the blood returning from the lower part of the body to the lungs.

Forecast

With proper treatment and monitoring, most people with Ebstein’s anomalies can have a long and healthy life, especially if the symptoms begin after the first year of age.

Most women with Ebstein anomalies who have well oxygenated blood can tolerate pregnancy with few or no complications.

People with a mild case of the disorder and without enlarged heart can participate in sports and physical activities.

People with moderate cases of Ebstein’s anomaly are advised to remain active, with medical guidance.

Ebstein’s anomaly can be serious, but it can also be well managed and should not prevent most people from living a full and healthy life.

The medications should be taken continuously and follow up visits with a cardiologist. Children with very severe cases because they may need additional surgeries throughout their lives.