American Board of Internal Medicine (ABIM) Certification Practice Exam

In a patient with coarctation of the aorta, where is the continuous murmur best heard?

1. Anterior thoracic wall

2. Right upper quadrant

3. Posterior interscapular area

4. Left lower abdomen

The correct answer is: Posterior interscapular area

In a patient with coarctation of the aorta, the continuous murmur is best heard in the posterior interscapular area. This is attributed to the collateral circulation that develops due to the narrowing of the aorta. As the aorta is coarcted, the blood flow is redirected through various collateral pathways, which can lead to increased turbulence in the blood flow. The posterior interscapular region is particularly significant as it corresponds to the area where collateral vessels, like the intercostal arteries, may become more prominent in order to supply blood to the lower body. This increased blood flow and subsequent turbulence result in the characteristic continuous murmur that can be auscultated in this location. Understanding the location of this murmur helps in diagnosing coarctation of the aorta and assessing the severity of the condition, as well as guiding further management strategies.