How is coarctation of the aorta defined?

The definition of coarctation of the aorta is centered around the specific anatomical location of the narrowing, which typically occurs just distal to the left subclavian artery, often near where the ductus arteriosus (in infants) or the ligamentum arteriosum (in older children and adults) is located. This particular narrowing leads to significant hemodynamic changes, as it can cause hypertension in the proximal portions of the aorta and diminished blood flow to the lower body.

Focusing on the choice regarding the narrowing around the insertion of the ductus or ligamentum arteriosum captures the essence of coarctation, which is critical for diagnosis and understanding the physiological implications. The specific location is also vital for surgical planning and treatment modalities, as interventions typically focus on this area to relieve the constriction and restore normal blood flow.

The other options describe various features or types of abnormal development or narrowing of the aorta, but they don't accurately match the anatomical definition of coarctation. The narrowing is not defined as occurring between the left ventricle and the aorta, as that describes a different condition. Segmental narrowing or anomalous development of the entire aortic arch are broader terms that may relate to other types