What is Ebstein’s Anomaly?
Ebstein’s Anomaly, a rare congenital heart defect, occurs when the tricuspid valve (the valve between the right atrium and right ventricle) of the heart does not form correctly and is lower into the right ventricle than normal. Normally, the tricuspid valve has three flaps that allow blood to flow from the right atrium into the right ventricle. In Ebstein’s Anomaly, due to the displacement of the tricuspid valve, the size of right ventricle is decreased and blood leaks backwards into the right atrium instead of being pumped to the lungs.
This heart defect can cause oxygen-poor blood to travel to the left side of the heart through a hole in the two top chambers and be pumped out to the body. This makes the baby have lower oxygen levels than normal.
Some children with Ebstein’s Anomaly have Wolff-Parkinson-White syndrome, a syndrome that leads to heart rhythm disorders (arrhythmias). Common symptoms after the baby is born with Ebstein’s include bluish skin, failure to thrive, breathing problems and a fast heartbeat.
How is Ebstein’s Anomaly diagnosed during pregnancy?
If the fetal tricuspid valve appears abnormal or is leaking and the heart is enlarged on a fetal ultrasound, Ebstein's anomaly may be suspected and a fetal echocardiogram (echo) will be performed. This safe, noninvasive test shows the structure of the fetal heart and how it is functioning. The impact of Ebstein’s Anomaly can range from mild to severe. Because of this, an experienced fetal heart team should help you decide on the best possible course of treatment.
How is Ebstein’s Anomaly in a fetus monitored during pregnancy?
Because severe cases of Ebstein’s Anomaly carry an increased risk of fetal demise compared to other congenital heart defects, close monitoring is important. Regular monitoring provides the Fetal Heart Program team with a picture of the fetus’s overall well-being, and can alert them to any changes that would require an early delivery.
How does Ebstein’s Anomaly impact delivery?
Most babies with a mild form of Ebstein’s Anomaly can be delivered vaginally, unless there are obstetric indications for another mode of delivery. It is best for these babies to be delivered at a medical center where there is access to a team of pediatric cardiologists and neonatologists, along with an established Neonatal Intensive Care Unit (NICU).
After delivery, the baby will need prostaglandin (PGE), an intravenous medication that keeps the patent ductus arteriosus (a normal connection present in babies in the womb) open. The patent ductus arteriosus (PDA) will allow blood flow to the lungs.
What are the treatments and surgery for Ebstein’s Anomaly?
For mild cases, medication may be all the child needs. For more severe cases surgery in the newborn period may be necessary.
There are a few possible surgeries, depending on the nature of the heart defect and the age of the child at the time of surgery:
- Surgical valve repair
- If possible, the surgeon repairs the structure of the tricuspid valve.
- Tricuspid valve replacement
- If the tricuspid valve cannot be surgically repaired, surgeons can replace the existing valve.
- Three-staged 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 typically performed in the first week of life. The surgeon sews over the leaking tricuspid valve (the valve between the right atrium and right ventricle), and then creates an extra connection (called a Blalock-Taussig shunt) to provide blood flow to the lungs.
- Glenn procedure
- This procedure typically occurs between four and six months of age. This surgery creates a direct connection between the pulmonary artery and the superior vena cava (vessel returning oxygen-poor blood from the upper part of the body to the heart). This reduces the work the right ventricle has to do by allowing blood returning from the upper body to flow directly to the lungs.
- Fontan procedure
- This procedure typically occurs between two and four years of age. This surgery connects the pulmonary artery and the inferior vena cava (vessel returning oxygen-poor blood from the lower part of the body to the heart), allowing the blood coming back from the lower body to go to the lungs. Once this procedure is complete, oxygen-rich and oxygen-poor blood no longer mix in the heart. The surgeon may leave a small connection between the oxygen rich and oxygen poor chambers (a fenestration).
- Radiofrequency ablation for arrhythmias
- Older children who have arrhythmias that medication can’t effectively control may need this minimally invasive procedure.
What happens after surgery?
Children who have Ebstein’s Anomaly will require monitoring and medication throughout their life. Children with more severe cases will need additional surgeries throughout their lifetime.
What is the long-term prognosis for children with Ebstein’s Anomaly?
The long-term prognosis after surgery for Ebstein’s Anomaly depends on the severity of the defect. The child will need lifelong follow-up visits with a cardiologist.