In this section
Absence of any connection between the right atrium and the right
ventricle leads to blood being diverted from the right atrium to
the left atrium. The right ventricle (RV) is usually small
(Hypoplastic) Survival depends on an associated VSD (often quite
small), in order for blood to reach the lungs, or on the ductus
remaining open in the early days of life. Affected infants may be
well in the early weeks of life, but gradually become blue as they
get older. Early surgery often involves a 'Shunt' operation,
involving insertion of a tiny piece of artificial tube (made from
Goretex) between the right or left arm artery and the pulmonary
artery to the respective lung.
Later a 'Cavo-Pulmonary shunt' may be performed. This involves
connecting the SVC (Superior Vena Cava) to the right Pulmonary
Artery, to direct blood from the upper part of the circulation into
the lungs without returning to the heart. Corrective surgery (a
"Fontan" operation) is carried out later in childhood. This results
in the blood flow from the IVC also passing directly to the lungs.
After this procedure the lung circulation operates without a
separate ventricle (as the right ventricle is too small to perform
its usual job). This only works satisfactorily when the lung
arteries are well developed and have not been damaged by the
effects of high pressure or other factors.