The advanced practice registered nurse (APRN) is performing a cardiovascular exam on a 75 year-old patient. The APRN auscultates a carotid bruit. Which condition is least likely to cause a carotid bruit?

A. Atherosclerosis is incorrect because it is a common cause of carotid bruits. Plaque buildup in the carotid arteries leads to turbulent blood flow, which produces the characteristic whooshing sound heard during auscultation. B. Carotid artery stenosis is incorrect because it directly causes narrowing of the carotid artery, resulting in turbulent blood flow and an audible bruit. This is one of the most classic causes of a carotid bruit. C. Aortic stenosis is incorrect because although it is a valvular heart condition, it can produce a systolic murmur that radiates to the carotid arteries, which may be mistaken for or contribute to a carotid bruit on auscultation. D. Tricuspid valve regurgitation is correct because it is least likely to cause a carotid bruit. This condition involves the right side of the heart and produces a holosystolic murmur best heard at the left lower sternal border, without radiation to the carotid arteries. It does not create turbulent flow in the carotid vessels.