Ebstein anomaly is a rare heart defect in which parts of the tricuspid valve are abnormal. The tricuspid valve separates the right lower heart chamber (right ventricle) from the right upper heart chamber (right atrium). In Ebstein anomaly, the positioning of the tricuspid valve and how it functions to separate the 2 chambers is abnormal.
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. Ebstein anomaly occurs as a baby develops in the womb. The exact cause is unknown, although the use of certain drugs (such as lithium or benzodiazepines) during pregnancy may play a role. The condition is rare. It is more common in white people.
Data for cases with Ebstein anomaly, as well as all live births, were obtained from the Texas Birth Defects Registry (TBDR) and Center for Health Statistics for the period 1999-2005.The overall prevalence was 0.72 per 10,000 live births. Variables associated with an increased prevalence of non-syndromic Ebstein anomaly included: maternal age >39 years (compared to those 20-24 years), maternal residence along the Texas-Mexico border (compared to non-border residence), and conception in fall or winter (compared to summer). In addition, infants with Ebstein anomaly were at a greater risk of preterm birth and being small for gestational age.
Symptoms range from mild to very severe. Symptoms develop soon after birth, and include bluish-colored lips and nails due to low blood oxygen levels. In severe cases, the baby appears very sick and has trouble breathing. In mild cases, the affected person may be asymptomatic for many years.
Treatment depends on the severity of the defect and the specific symptoms. Medical care may include:
• Medications to help with heart failure
• Oxygen and other breathing support
• Surgery to correct the valve may be needed for children who continue to worsen or who have more serious complications