AS HemodynamicsInteractive lab
v2.0 · Educational tool
Beta version v2.0 · Educational use only · Not clinically validated.Not intended to determine aortic stenosis severity or guide clinical management.
Aortic stenosis hemodynamics

The gradient does not exist in isolation.

Adjust flow, change valve area, and watch the gradient move in real time. A visual laboratory for understanding discordance, not just individual numbers.

Relationship exploredΔP = [ Q / (44.3 × AVA) ]²

Rearranged form of the Gorlin relationship, with Q expressed in mL/s.

02

Dynamic nomogram

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

THE CONCEPTsame SV ≠ same flow

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

Method and limitations

A tool for reasoning,
not for closing the case.

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.