Which congenital heart defect is characterized by decreased systemic blood flow?

Coarctation of the aorta is characterized by a narrowing of the aorta, which can significantly impact systemic blood flow. In this condition, the obstruction typically occurs just distal to the left subclavian artery. Due to this narrowing, the blood flow to the lower body is reduced while blood flow to the head and upper body often remains relatively normal.

This decrease in systemic blood flow leads to various clinical manifestations, including hypertension in the upper body and hypotension in the lower body. The affected neonates may present with signs of heart failure or poor perfusion to the lower extremities, emphasizing the severity of the decreased systemic blood flow.

In contrast, pulmonary stenosis, ventricular septal defect, and atrial septal defect do not primarily result in decreased systemic blood flow. Instead, these conditions may lead to pulmonary over-circulation or other hemodynamic changes, but they do not typically cause the systemic flow reductions associated with coarctation of the aorta. Understanding this condition is crucial for identifying symptoms and implementing appropriate interventions in neonatal care.