Pathophysiology: The tricuspid valve is normally made of three parts, called leaflets or flaps. The leaflets open to allow blood to move from the right atrium (top chamber) to the right ventricle (bottom chamber) while the heart relaxes. They close to prevent blood from moving from the right ventricle to the right atrium while the heart pumps.
In persons with Ebstein anomaly, the leaflets are placed deep in the right ventricle instead of the normal position. The leaflets are often larger than normal. The defect most often causes the valve to work poorly, and blood may go the wrong way. Instead of flowing out to the lungs, the blood flows back into the right atrium. The backup of blood flow can lead to heart enlargement and fluid buildup in the body. There may be narrowing of the valve that leads to the lungs (pulmonary valve).
In many cases, patients also have a hole in the wall separating the heart's two upper chambers (atrial septal defect) and blood flow across this hole may cause oxygen-poor blood to go to the body. This can cause cyanosis, a blue tint to the skin caused by oxygen-poor blood.
Clinical Features: Mild forms of Ebstein's anomaly may not cause symptoms until later in adulthood. If signs and symptoms are present, they may include:
- Shortness of breath, especially with exertion
- Heart palpitations or abnormal heart rhythms (arrhythmias)
- A bluish discoloration of the lips and skin caused by low oxygen (cyanosis)
Diagnosis: On history and physical examination if Ebstein anomaly is suspected following workup help in the diagnosis:
1. Echocardiogram: is often used to diagnose many of the congenital heart defects including Ebstein anomaly.
2. Chest X ray: will reveal an enlarged heart (see picture above)
3. ECG: About 50% of individuals with Ebstein's anomaly have evidence of Wolff-Parkinson-White syndrome, secondary to the atrialized right ventricular tissue.
4. Cardiac MRI; may help determine the severity of the condition and give a detailed view of the tricuspid valve.
Management: Treatment depends on the severity of the defect and the specific symptoms. Medical care may include:
- Medications to help with heart failure, such as diuretics
- Oxygen and other breathing support
- Surgery to correct the valve
- Replacement of the tricuspid valve. This may be needed for children who continue to worsen or who have more serious complications.