What is a key method for diagnosing coarctation of the aorta?

The key method for diagnosing coarctation of the aorta is comparing upper and lower extremity blood pressures. In patients with this condition, a significant difference in blood pressure readings between the arms (upper extremities) and the legs (lower extremities) is often observed. Typically, blood pressure will be higher in the arms due to the narrowed section of the aorta preventing adequate blood flow to the lower body. This diagnostic approach is essential in clinical practice as it can help to identify the presence of coarctation and guide further diagnostic evaluation and management.

While other diagnostic methods such as listening for abnormal heart murmurs, which may indicate associated heart defects, and X-ray imaging, which can reveal indirect signs of coarctation, are certainly useful, they do not provide the specific information about blood flow and pressure differences that is characteristic of coarctation of the aorta. Similarly, assessing pulse strength in the femoral artery can give clues about blood flow but comparing blood pressures is a more standardized and definitive diagnostic criterion for this condition.