|Carotid bruit in a gentleman with a 70% stenosis of his left carotid artery.|
It may occur as the result of carotid artery stenosis (though some disagree); however, most carotid bruits, particularly those found in younger or asymptomatic patients, are not related to any disease and are termed "innocent carotid bruits". A carotid bruit is unlikely to be heard if the stenosis occludes less than 40% of the diameter of the artery. Likewise, a stenosis of greater than 90% may not be heard, as the flow may be too low.
Many carotid bruits are discovered incidentally in an otherwise asymptomatic patient. The presence of a carotid bruit alone does not necessarily indicate the presence of stenosis, and the physical examination cannot be used to estimate the degree of stenosis, if present; therefore, any bruit must be evaluated by ultrasound or imaging.
Pronunciation and terminology
Bruit is traditionally pronounced broot, rhyming with boot, although the etymologically accurate pronunciation bru´e or bru-e´ is common in North American medical parlance. In addition, while bruit and murmur are technically synonymous, the term bruit is generally reserved for arterial sounds in North America.
- MATTHEWS WB (May 1961). "OBSERVATIONS ON THE CAROTID BRUIT". J. Neurol. Neurosurg. Psychiatry. 24 (2): 161–6. doi:10.1136/jnnp.24.2.161. PMC 495382. PMID 13768297.
- Mayock R (September 2007). "Does a carotid bruit predict cerebrovascular complications following noncardiac surgery in asymptomatic patients?". Cleve Clin J Med. 74 Suppl 1: S18–9. PMID 18368873.
- Bates' Guide to Physical Examination and History Taking, 9th Ed, Chapter 20
- DeGowin's Diagnostic Examination, 9th Edition, Chapter 8; Richard F. LeBlond, Donald D. Brown, Richard L. DeGowin
- Stedman's Medical Dictionary - 28th Ed.