How can dynamic LVOT obstruction be distinguished from fixed AS on Doppler?

• A. Dynamic LVOT obstruction shows gradient variability with maneuvers and LVOT geometry changes; fixed AS shows persistent high gradients independent of maneuvers.
• B. Dynamic LVOT obstruction shows gradient variability with maneuvers and LVOT geometry changes; fixed AS shows persistent high gradients independent of maneuvers.
• C. LVOT obstruction is never detected by Doppler.
• D. They are indistinguishable on Doppler.

Answer: (A)