What structural defect is necessary for oxygenation in tricuspid atresia?

In the context of tricuspid atresia, an understanding of the associated structural defects is crucial for ensuring adequate oxygenation. Tricuspid atresia is a congenital heart defect characterized by the absence or malformation of the tricuspid valve, which fails to connect the right atrium to the right ventricle. This defect leads to a situation where blood cannot flow from the right atrium to the right ventricle, impeding typical pulmonary circulation for oxygenation.

For patients with tricuspid atresia to maintain some level of oxygenated blood flow, certain structural defects become essential. The presence of a patent ductus arteriosus (PDA), atrial septal defect (ASD), or ventricular septal defect (VSD) allows for mixing of deoxygenated and oxygenated blood between the systemic and pulmonary circulations. Specifically, the PDA enables blood to flow from the aorta to the pulmonary artery, while the ASD provides a pathway for blood to move from the right atrium to the left atrium, subsequently flowing into the systemic circulation. The VSD allows blood to shunt from the left ventricle into the right ventricle, where it can eventually reach the lungs.

Without these defects