What left atrial appendage flow velocity is associated with an increased risk of thrombus formation?

What left atrial appendage flow velocity is associated with an increased risk of thrombus formation?

• A. < 0.2 m/s
• B. ≥ 0.3 m/s
• C. 0.6 m/s
• D. 1.0 m/s

Answer: (A)

Low left atrial appendage flow velocity indicates blood stasis, which promotes thrombus formation. When the LAA empties very slowly, specifically less than 0.2 m/s (about 20 cm/s), the risk of clot development and subsequent embolization is highest. The other values reflect progressively better flow: velocities around 0.3 m/s or higher show more organized flow with less stasis, meaning a lower thrombus risk. Thus, the velocity below 0.2 m/s is the finding most strongly linked to thrombus formation.

Low left atrial appendage flow velocity indicates blood stasis, which promotes thrombus formation. When the LAA empties very slowly, specifically less than 0.2 m/s (about 20 cm/s), the risk of clot development and subsequent embolization is highest. The other values reflect progressively better flow: velocities around 0.3 m/s or higher show more organized flow with less stasis, meaning a lower thrombus risk. Thus, the velocity below 0.2 m/s is the finding most strongly linked to thrombus formation.