Conditions Valve lesions

Mitral regurgitation

Systolic leak into the LA. Total LV exceeds forward stroke volume; the LA pressure response depends on LA : a normal-sized stiff LA (acute MR) shows a large v wave, a dilated compliant LA (chronic MR) absorbs the same volume with a small pressure rise.

Experiment: Normal adult at rest · unchanged from its starting state

Key measurements

Mitral regurgitant fraction

— %

baseline not set

LA v wave (peak)

— mmHg

baseline not set

— mmHg

baseline not set

Forward aortic stroke volume

— mL

baseline not set

— %

baseline not set

Inspect beats and technical detailsbeat selection, transient versus settled, timings

Position within the beat0.000 s

Early beats after a change are transient: the circulation is still re-balancing. A beat is called settled when three consecutive windows agree within the tolerance. Playback speed only moves the cursor over the finished simulation; it never changes the heart rate.

Compare scenariosbaseline, snapshots, axes, export

Baseline

No baseline is set.

Comparison snapshots

Keep up to three snapshots of states you want to compare with the baseline and the current state.

How comparisons are drawn

Side-by-side loops instead of an overlay Identical axes for every loop (turn off and each plot rescales to its own data)

Pressure–volume loop options

Show the ESPVR and EDPVR reference lines Shade stroke work Show the arterial elastance (Ea) line Show the right heart instead of the left

Export

Choose a version

Differences from normal: mitral regurgitant orifice 0 → 0.4 cm² with unchanged LA and LV. Expected: large LA v wave, raised wedge pressure, total LV stroke volume far above forward stroke volume, reduced forward output.

What to look for

Large LA v wave in acute MR; small in chronic MR for the same orifice
No isovolumic contraction: ejection into the LA begins as soon as LV pressure exceeds LA pressure
Forward output below total

Try it

Set values directly

Mitral regurgitant orificecm²

How this works

Regurgitant orifice area for the mitral valve. 0 = competent.

Changes: valves.mv.regurgitantArea

Compare scenariosloads two scenarios side by side

Acute vs chronic MR

Same regurgitant orifice; LA compliance sets the v wave and the wedge pressure. A large v wave is not a stand-alone severity grade.

Common misconception. A large v wave does not by itself grade MR severity; it depends on LA and can be absent in severe chronic MR.

Apply it

Afterload reduction in acute severe MR mainly helps by:

Lowering aortic pressure so more of the stroke volume goes forward instead of into the LARaising contractilityStiffening the LA

← Mitral stenosis Tricuspid regurgitation and stenosis →

Sources & model detailsreview status, testing, limitations

Sources

Content review

Teaching text and answer keys: Proposed. None of the 2 source claims behind it has been expert reviewed. Where a question has more than one defensible answer, more than one is accepted.

Simulation testing

Finding Hemo closed-loop lumped-parameter model: Quantitatively tested. Software, conservation and qualitative pattern tests pass. Not expert reviewed; normal ranges and phenotype parameter sets are proposed teaching values.
Scenario “Normal adult at rest” is checked for: closed-system volume conservation (<0.1% over 100 beats); timestep sensitivity (<1% change in core stable measurements at dt/2); seeded repeatability; resting pressures, volumes and flows within stated textbook ranges; directional response to fluid bolus and afterload increase.

Passing these tests means the equations are solved correctly and behave as stated. It does not mean the teaching statements, parameter values or answer keys have been expert reviewed.

Limitations that matter here

Quantitative compartment model: regurgitant orifice and chamber compliances; no leaflet or annular mechanics.
Reflexes are off: no autonomic compensation follows a change (the optional baroreflex is not enabled).
Constant intrathoracic pressure -3 mmHg (respiratory swing disabled).

Technical details

Model: fh-closed-loop 0.4.0
App / content version: 0.5.0 / 0.5.0
Scenario id: normal-adult
Solver: rk4, dt 0.2 ms
Condition id: mitral-regurgitation