Family Nurse Practitioner Exam

In an infant with coarctation of the aorta, what would be the expected blood pressure readings?

1. Higher in the arms than in the legs

2. Only diastolic higher in the legs

3. Higher in the legs than the arms

4. Lower in both arms than in the legs

The correct answer is: Higher in the arms than in the legs

In cases of coarctation of the aorta, which is a congenital condition characterized by a narrowing of the aorta, the expected blood pressure readings show higher values in the arms than in the legs. This occurs because the area beyond the coarctation (often downstream to the left subclavian artery) experiences reduced blood flow and pressure due to the narrowing. Therefore, the upper body, including the arms, receives more blood supply and thus registers higher blood pressure compared to the lower body, specifically the legs, which are subject to the effects of the coarctation. Recognizing this pattern is essential for the diagnosis of coarctation of the aorta, as the differential blood pressure readings provide vital clues. Infants with this condition often exhibit signs of poor perfusion in the lower extremities, and the contrast in blood pressure can aid healthcare providers in assessing the severity of the narrowing and guiding further management. The presence of higher blood pressure in the arms compared to the legs is a classic teaching point in pediatric cardiology.