In this condition, there's no tricuspid valve. That means 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 called an atrial septal defect and usually an opening in the wall between the two ventricles called a ventricular septal defect. Because the circulation is abnormal, the blood cannot get enough oxygen, and the child looks blue (cyanotic).
Often in these cases a surgical shunting procedure is needed to increase blood flow to the lungs. This reduces the cyanosis. If the right ventricle is too small to be a good pumping chamber, then the surgeon can connect the right atrium directly to the pulmonary artery. The atrial defect also can be closed to relieve the cyanosis. This is called a Fontan procedure. Children with tricuspid atresia require lifelong follow-up by a pediatric cardiologist.
People with tricuspid atresia, before and after treatment, are at risk for getting an infection of the valves (endocarditis). To help prevent this, they'll need to take antibiotics before certain dental and surgical procedures.