How Common is EA?

EA: How Common Is it?

Ebstein's Anomaly (EA) is a very rare heart condition which affects the tricuspid valve separating the upper and lower chambers on the right side of the heart. EA occurs in less than one newborn out of 200,000.[2]

More than half of all EA cases are first identified by an ultrasound of the mother's pelvic region before birth.

Of the cases detected before birth, 3 out of 10 of the infants will not survive the first year and 5 out of 10 will not survive until the age of 30. If EA is detected after birth, meaning there are no signs of EA until childhood or during the teenage years, survival rates are much better; more than 8 out of 10 of these individuals live into their 30s.[3]

Due the low occurrence of EA in the population and other heart conditions that also occur in people with EA, the exact number of individuals with EA is difficult to assess. The Centers for Disease Control and Prevention (CDC) often includes EA in the category of "critical congenital heart defects." The CDC includes EA in the list of important congenital heart defects that the medical team checks for in newborn ultrasound screenings. These screenings are usually done in the first 24 hours of the baby's life, before they are sent home from the hospital. The true number of individuals born with Ebstein's Anomaly each year in the United States needs to be further studied.

What other medical problems might be present in a child with EA?
EA often does not occur alone. Most individuals with EA have other heart problems, too. Other diseases that also be present in infants or children with EA are:

• Pulmonary atresia - This occurs when the valve that lets blood flow from the right ventricle to the lungs (pulmonic valve) does not form correctly. No blood is allowed to enter the lungs from the heart to get oxygen and the cells of the body, which depend on oxygen, suffer. This defect requires surgery.[4]
• Coarctation of the aorta - The aorta, a large vessel that carries oxygen-rich blood to the body, is narrowed in coartation of the aorta. So the heart has to pump much harder to get enough oxygen-rich blood to the body. [5]
• Ventricular septal defect - A hole in the wall that separates the lower chambers of the right and left sides of the heart (the ventricle). This causes some of the oxygen-rich blood to be pumped back into the lungs, rather than being pumped to the body's cells through the aorta.[6] 
• Tetralogy of Fallot - A rare condition caused by four heart defects which affect the structure of the heart. The result, like EA, is that oxygen-poor blood reaches the cells of the body. Children with this condition usually have blue-tingled skin. [7]
• Atrioventricular septal defect - Holes in the walls separating the upper chambers of the heart (atria) and lower chambers of the heart (ventricles). This results in extra blood flowing to the lungs and overwork of the heart. Eventually the heart may enlarge. [8]
• Mitral valve prolapse - The mitral valve separates the upper and lower left chambers of the heart. In mitral valve prolapse the flaps of the valve bulge upward into the left upper chamber as the heart contracts so oxygen-rich blood sometimes leaks backwards from the left ventricle to the left atrium. [9]

Figure 2. An ultrasound image of a heart with Ebstein's Anomaly (EA). This
image shows the displacement of the tricuspid valve (TV) into the right ventricle
 (RV). the right atrium (RA) is bigger than normal. This is how a baby's heart
would appear on an ultrasound when diagnosed with EA. [10]

References

2. Osiro S, Tiwari KJ, Mathenge N, et al. When Lithium Hurts: A Look at Ebstein Anomaly. Cardio in Rev. 

          October 2013: 21(2): 257-263. doi: 10.1097/CRD.0b013e318280c966

3. Lupo PJ, Langlois PH, Mitchell LE. Epidemiology of Ebstein Anomaly: Prevalence and patterns in Texas, 1999-2005.            Am J Med Gen Pt A. May 2011: 155(5): 1007-1014. doi: 10.1002/ajmg.a.33883
4. Pulmonary atresia. The Mayo Clinic Web site. Availabe from: http://www.mayoclinic.org/diseases-conditions/pulmonary-atresia/basics/definition/con-20030896. Accessed January 15, 2015. 
5.Coarctation of the aorta. The Mayo Clinic Web site. Available from: http://www.mayoclinic.org/diseases-conditions/coarctation-of-the-aorta/basics/definition/con-20031772. Accessed January 15, 2015.
6. Ventricular septal defect. The Mayo Clinic Web site. Availabe from: http://www.mayoclinic.org/diseases-conditions/ventricular-septal-defect/basics/definition/con-20024118. Accessed January 15 ,2015. 
7. Tetraology of Fallot. The Mayo Clinic Web site. Available from: http://www.mayoclinic.org/diseases-conditions/tetralogy-of-fallot/basics/definition/con-20043262. Accessed January 15, 2015. 
8. Atrioventricular Canal Defect. The Mayo Clinic Web site: http://www.mayoclinic.org/diseases-conditions/atrioventricular-canal-defect/basics/definition/con-20024932. Accessed January 15, 2015.
9. Mitral Valve Prolapse. The Mayo Clinic Web site. Available from: http://www.mayoclinic.org/diseases-conditions/mitral-valve-prolapse/basics/definition/con-20024748. Accessed January 15, 2015.
10. Ultrasound of Ebstein's Anomaly. The Ultrasound of Life Web site. Available from: http://www.fetalultrasound.com/online/text/7-070.HTM. Accessed January 15, 2015.