In Doppler evaluation, what does post-stenotic turbulence indicate?

In Doppler evaluation, what does post-stenotic turbulence indicate?

• A. Laminar flow immediately downstream
• B. Turbulent flow at the stenosis mouth
• C. No flow after the stenosis
• D. Turbulent flow distal to the stenosis

Answer: (D)

Post-stenotic turbulence occurs because the narrowed segment accelerates the blood jet, and as the flow exits the stenosis it expands and decelerates, leading to flow separation and eddies downstream. This disrupted flow is what Doppler detects as turbulent or disturbed flow distal to the stenosis, often with spectral broadening. It’s not laminar right after the narrowing, not zero flow, and turbulence at the stenosis mouth would be at the narrowest point itself rather than downstream. Thus, turbulent flow distal to the stenosis best explains post-stenotic turbulence.

Post-stenotic turbulence occurs because the narrowed segment accelerates the blood jet, and as the flow exits the stenosis it expands and decelerates, leading to flow separation and eddies downstream. This disrupted flow is what Doppler detects as turbulent or disturbed flow distal to the stenosis, often with spectral broadening. It’s not laminar right after the narrowing, not zero flow, and turbulence at the stenosis mouth would be at the narrowest point itself rather than downstream. Thus, turbulent flow distal to the stenosis best explains post-stenotic turbulence.