Final answer:
Tricuspid atresia is a congenital heart defect with the absence of the tricuspid valve, requiring PGE1 treatment to maintain ductus arteriosus patency until surgery.
Step-by-step explanation:
Tricuspid atresia is a congenital heart defect where the tricuspid valve, a one-way opening between the atrium and the ventricle on the right side of the heart, fails to develop. This condition disrupts normal blood flow through the heart and requires prompt medical intervention. Treatment for tricuspid atresia often involves the administration of PGE1 (prostaglandin E1), a medication that helps to maintain the patency of the ductus arteriosus, a vital pathway for blood circulation in the absence of a functioning tricuspid valve, until a more definitive surgical procedure can be performed.