Tricuspid atresia

February 25th, 2007

(Note: It will be helpful to review normal heart function before reading this.)

In this condition, there’s no tricuspid valve so no blood can flow from the right atrium to the right ventricle. As a result, the right ventricle is small and not fully developed.

The child’s survival depends on there being an opening in the wall between the atria (atrial septal defect) and usually an opening in the wall between the two ventricles (ventricular septal defect). As a result, the venous (bluish) blood that returns to the right atrium flows through the atrial septal defect and into the left atrium. There it mixes with oxygen-rich (red) blood from the lungs. Most of this poorly oxygenated mixture goes from the left ventricle into the aorta and on to the body. The rest flows through the ventricular septal defect into the small right ventricle, through the pulmonary artery and back to the lungs. Because of this abnormal circulation, the child looks blue.

Often in these children it’s necessary to do a surgical shunting procedure to increase blood flow to the lungs. This reduces the cyanosis. Some children with tricuspid atresia have too much blood flowing to the lungs. They may need a procedure (pulmonary artery banding) to decrease blood flow to the lungs.

Other children with tricuspid atresia may have a more functional repair (Fontan procedure). In this, a connection is created between the right atrium and pulmonary artery. The atrial defect is also closed. This eliminates the cyanosis but, without a right ventricle that works normally, the heart can’t work totally as it should.

Children with tricuspid atresia require lifelong follow-up by a cardiologist for repeated checks of how their heart is working. They also risk infection in the heart’s valves (endocarditis) before and after surgery. They should get antibiotics such as amoxicillin before dental work and certain surgeries to help prevent endocarditis. Good dental hygiene also lowers the risk of endocarditis.

For more information about dental hygiene and preventing endocarditis, ask your pediatric cardiologist.