Pulmonary atresia with a ventricular septal defect (PA/VSD) is the most severe form of tetralogy of Fallot. A large ventricular septal defect is present, and only one artery comes off the heart. This artery, called the aorta, supplies blood to both the lungs and the body.
In babies with PA/VSD, the pulmonary valve never developed, so blood gets to the lungs from the aorta via a patent ductus arteriosus (PDA) or multiple aortopulmonary collateral arteries. PA/VSD accounts for 2 percent of congenital heart disease. It is a relatively common cause of cyanosis (blueness) in newborn babies. Children with PA/VSD sometimes have a chromosomal disorder called DiGeorge syndrome, which can cause the child to have low calcium levels in the blood, to have more infections than normal, and to have learning disabilities.
PA/VSD is a congenital heart defect that can be discovered during pregnancy by fetal echocardiography. It can also be detected with the routine testing done on all newborns in the hospital nursery when they are checked for critical congenital heart disease.
Severe cyanosis (blueness) results from PA/VSD if not enough blood gets to the baby’s lungs. Sometimes, if there are multiple collateral arteries or a large PDA supplying the lungs, a baby’s oxygen level can remain normal. Most of the time, an echocardiogram (cardiac ultrasound) is enough to make the diagnosis, however if the cardiologist feels it is necessary, then other tests such as cardiac catheterization or cardiac CT scanning are used to identify all of the blood vessels that supply the lungs and to determine the coronary artery anatomy.
Cardiac surgery is usually offered to treat PA/VSD. The strategy is to connect the right ventricle to all of the collateral arteries with a valved tube. The ventricular septal defect may be partially or completely closed. Sometimes multiple operations are needed to complete the repair in stages. A pediatric cardiologist can help you understand this type of congenital heart disease and can manage your child’s heart condition.