Carotid bruit

It may occur as the result of carotid artery stenosis[1] (though some disagree);[2] however, most carotid bruits, particularly those found in younger or asymptomatic patients, are not related to any disease and are termed "innocent carotid bruits".[3] 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.[4]

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.[5] In addition, while bruit and murmur are technically synonymous, the term bruit is generally reserved for arterial sounds in North America.[4]