WHERE SHOULD YOU PLACE THE LVOT DOPPLER SAMPLE? Calculating aortic valve area using the continuity equation requires an accurate LVOT velocity-time integral (VTI). But a few millimetres can make a difference. 1. Start in the LVOT Use pulsed-wave Doppler and position the sample volume below the aortic valve. 2. Move toward the valve Advance the sample volume gradually toward the aortic valve, observing the spectral waveform. 3. Identify the optimal position As the sample enters the flow acceleration zone, spectral broadening appears. This indicates that the sample is too close to the valve. 4. Move slightly apically Withdraw the sample until spectral broadening disappears and a clear, laminar LVOT signal is obtained. Why does this matter? If the sample is too close to the valve, the measured LVOT VTI may be falsely elevated, causing the calculated aortic valve area to be overestimated. If it is too far into the ventricle, the measurement may not represent the appropriate LVOT flow velocity. Clinical pearl: Correct LVOT sample positioning is essential for reliable grading of aortic stenosis. Reference: ASE recommendations for echocardiographic assessment of aortic stenosis; 2025 ESC/EACTS Guidelines for the Management of Valvular Heart Disease.