Conditions Cardiomyopathy and pericardium

Obstructive hypertrophic cardiomyopathy

A hypercontractile, small LV whose outflow tract narrows as the cavity empties (systolic anterior motion). Unlike fixed AS, the gradient is dynamic: it increases when or falls, when rises, and on the beat after a PVC.

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

Key measurements

Dynamic LVOT peak gradient

— mmHg

baseline not set

— mL

baseline not set

— mL

baseline not set

Aortic pulse pressure

— mmHg

baseline not set

— mmHg

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: dynamic LVOT orifice enabled (area 4 cm² falling to half at LV volume 75 mL, width 8 mL); LV Ees 2.6 → 4.0; passive stiffness k 0.014 → 0.02; LA stiffness 0.04 → 0.05. Expected: late-peaking LVOT gradient that increases with reduced preload, reduced afterload, increased contractility and after a PVC (Brockenbrough–Braunwald–Morrow: gradient up, aortic pulse pressure down).

What to look for

Late-peaking LVOT gradient
Gradient rises with blood loss, vasodilation, and Valsalva; falls with vasoconstriction
Post-PVC beat: gradient up, aortic pulse pressure down (Brockenbrough–Braunwald–Morrow)

Try it

Set values directly

LVOT obstruction onset volumemL

How this works

LV volume below which the outflow area halves; higher values obstruct earlier in ejection.

Changes: lvot.vCrit

Compare scenariosloads two scenarios side by side

HOCM vs fixed AS

Apply blood loss 500 mL to each: the HOCM gradient rises, the AS gradient falls.

Common misconception. The post-PVC rise in gradient alone is not the sign; in fixed AS the gradient also rises because of the larger . The sign is the fall in aortic pulse pressure.

Apply it

A patient with HOCM becomes hypotensive after a diuretic and a vasodilator. The first haemodynamic step is to:

Restore preload and afterload (fluid, vasoconstrictor); avoid inotropesStart dobutamineIncrease the vasodilator

← Tricuspid regurgitation and stenosis Tamponade, constriction and restriction →

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 with a volume- and contractility-dependent orifice (teaching approximation of SAM); no mitral leaflet mechanics or MR from SAM.
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: hocm