Aortic Stenosis Haemodynamics Lab
v2.3 · Educational tool
Beta version v2.3 · Educational use only · Not clinically validated.Not applicable to patients with a bicuspid aortic valve. Not intended to determine aortic stenosis severity or guide clinical management.

Measurement coherence in aortic stenosis

LVOT diameter review and comparison of flow rate, valve area and mean gradient.

1

Anatomical coherence

Check the measured LVOT against body size before exploring haemodynamics.

Predicted LVOT22.360 mmΔ measured − predicted— mm

Enter the measured LVOT to complete the check.

Leye reference: LVOT = 5.7 × BSA + 12.1 mm. The ±2 mm band prompts review; it does not certify accuracy or replace the measurement.

2

Haemodynamic coherence

3

Flow rate and mean gradient

Hover over the chart to follow the selected AVA curve.

On small screens, swipe horizontally to explore the chart.

Flow rate and mean gradient according to the Gorlin relationship020406080100120100150200250300350400Transvalvular flow rate, Q (mL/s)Mean gradient (mmHg)Q < 200250 reference40 mmHg
AVA 0.5
AVA 0.6
AVA 0.7
AVA 0.8
AVA 1.0
AVA 1.2
measured expected

Gorlin model: MG = [Q / (44,3 × AVA)]²

Scenario comparisonFreeze the current point, then change the inputs.
4

Results

Flow reference values
FLOW THRESHOLD200 mL/s

A commonly studied cut-off for defining reduced resting transvalvular flow rate.

LOW STROKE VOLUME≤35 mL/m²

Conventional threshold for indexed stroke volume; Q adds the time dimension.

EJECTION TIMEQ = SV / LVET

A longer ejection time reduces Q and may keep the gradient low even when SVi is preserved.

Model and limitations

The nomogram uses the simplified Gorlin relationship AVA = Q / (44.3 × √ΔP). This hydraulic model is derived from invasive hemodynamics: it is not interchangeable with Doppler continuity-equation AVA and does not incorporate pressure recovery, the instantaneous flow profile, LVOT measurement error, or dynamic changes in orifice area.

The displayed categories are descriptive and do not constitute a diagnosis or treatment recommendation. Discordant findings require technical review, assessment of blood pressure and loading conditions, multimodality imaging, and integrated clinical judgment.