What characterizes coarctation of the aorta?

Coarctation of the aorta is characterized primarily by the narrowing of a segment of the aorta, which can occur anywhere along its length but most commonly occurs just distal to the left subclavian artery. This narrowing creates a constriction that impedes blood flow, leading to differential blood pressure measurements in the upper and lower extremities.

In patients with coarctation, the upper body often shows higher blood pressure readings than the lower body due to the obstruction. This condition can result in various clinical manifestations, including hypertension in the arms and hypotension in the legs, heart failure, and even rips in the aorta due to increased strain.

Other options, such as widening of the aorta, absence of the aortic valve, and reversal of the aorta and pulmonary artery, do not apply to coarctation. The primary pathological feature is the significant and specific narrowing that results in the characteristic hemodynamic changes associated with this condition.