Ebstein’s anomaly (also called Ebstein’s malformation or simply Ebstein anomaly) is a defect that mainly affects the tricuspid valve. The tricuspid valve controls blood flow between the heart’s upper-right chamber (the right atrium) and lower-right chamber (the right ventricle). In Ebstein’s anomaly, the tricuspid valve is located lower than it should be, so the upper part of the right ventricle is part of the right atrium. This means that the right ventricle is too small and the right atrium is too large.

Besides being too low, the tricuspid valve may not be formed correctly. Heart valves are made up of flaps called leaflets. When the leaflets are normal, they act like doors, which control blood flow by opening and closing. But in Ebstein’s anomaly, abnormal leaflets may let blood leak back into the atrium after it has flowed into the ventricle. This backward flow of blood makes the atrium even larger and the ventricle even smaller.

People born with Ebstein’s anomaly often have other heart problems, including

• Atrial septal defect
• Pulmonary stenosis
• Pulmonary atresia
• Arrhythmias, especially atrial fibrillation and Wolff-Parkinson-White syndrome (also called pre-excitation syndrome)

How is it treated?

Treatment for Ebstein’s anomaly depends on how severe the condition is. In some cases, surgery may be needed.