Tricuspid atresia is a congenital condition who’s cause isn’t well understood, and is not as common as the other heart defects that obstruct or decrease pulmonary blood flow.
And, if there’s no alternate route to direct the blood flow, there would be virtually no blood in the right ventricle available to be pumped to the lungs for oxygenation.
Luckily, additional defects that present with this disorder; an ASD, patent foramen ovale, or PFO, and a VSD; provide a substitute route for the blood that would otherwise be trapped on the right side.
So, blood from the right atrium flows through the ASD or PFO to the left atrium, eventually making its way down to the left ventricle then out through the aorta; and blood from the left ventricle flows through the VSD into the right ventricle, eventually making its way through the pulmonary artery then to the lungs.
However, it’s important to note that all of this leads to mixing of poorly oxygenated and highly oxygenated blood.
Cyanosis, tachycardia, heart murmur and dyspnea are the most common early manifestations of tricuspid atresia, often noted at birth; while older children can exhibit signs of chronic hypoxemia, like clubbing of fingers and toes, as a result of long-term desaturated blood circulating in the body.
Though tricuspid atresia can be discovered during a prenatal ultrasound, diagnosis can be made through physical exam and diagnostic tests, like ECGs, echocardiogram, chest x-ray, cardiac catheterization, MRI of the heart and CT of the heart. Once tricuspid atresia is confirmed, treatment is started.
This generally consists of first initiating prostaglandin E1 to the newborn to keep the ductus arteriosus open until surgery can be performed.