Historical Overview
- Bruit is from the French word braire, to bray or roar. It refers to sounds heard from blood vessels.1
Description
- A bruit occurs when there is acceleration in the velocity of blood in the circulation, which produces acoustic vibrations.2
- In most cases, a bruit heard over an aneurysm indicates disruption of normal laminar blood flow in that or a nearby artery.1
Pathophysiology
- A bruit may arise from vaso-occlusive disease, atherosclerotic disease or upper extremity arterial aneurysm.
- “Innocent” thoracic bruits, not indicating pathology, may be heard in some patients from childhood through their mid-30s.1
Instructions
- Obtain an accurate and complete patient history3
- In a quiet room, apply gentle pressure with a stethoscope to listen for the sounds of turbulent blood flow
- If a bruit is heard during the auscultation, assess the volume, pitch and duration
- The sound created by an upper extremity arterial aneurysm that may produce a bruit can also be identified using Doppler
Variations
- Also check for thrills, or palpable vibratory sensations, over a vessel in which a bruit is heard. In these situations, a Doppler exam would be indicated.
Related Signs and Tests
- Radial artery pulse
- Ulnar artery pulse
- Allen test
- Doppler
Diagnostic Performance Characteristics
- Related tests should be carried out in conjunction with the bruit test. Bruits associated with arterial stenosis are not usually heard until an artery is ≥50% occluded.4