Bruit is more likely to be heard when flow velocity is very high. Which velocity is given as an example?

• A. 120 cm/sec
• B. 391 cm/sec
• C. 50 cm/sec
• D. 160 cm/sec

Answer: (B)

A bruit is produced when flow becomes turbulent as it accelerates through a narrowed vessel. When velocity rises, the jet through the stenosis creates chaotic eddies and pressure fluctuations that vibrate the vessel wall and surrounding tissues, making an audible sound with a stethoscope.

An example velocity of 391 cm/sec reflects a very high-velocity jet, which is the kind of flow that tends to generate a bruit. Lower velocities, such as 50, 120, or 160 cm/sec, are much less likely to produce audible turbulence unless other factors amplify the sound.