What view is preferred to measure LVOT diameter for continuity equation calculations, and how should the measurement be performed?

• A. Apical 4-chamber view; measure outer-edge to outer-edge in diastole; use a single measurement.
• B. Parasternal short-axis view at the level of the mitral valve; measure inner-edge to inner-edge in systole.
• C. Subcostal view; measure inner-edge to inner-edge in diastole; take two measurements.
• D. Parasternal long-axis view at the level of the aortic valve annulus; measure inner-edge to inner-edge in systole with minimal foreshortening; use the mean of multiple measurements.

Answer: (D)