How the model works
Sound markers are illustrative valve-event annotations with pressure-dependent timing.
The Wiggers sound layer marks M1/T1 and A2/P2 components, ejection clicks, prolapse clicks, opening snaps and selected gallops/knock. These are timing annotations, not patient phonocardiograms or a complete acoustic simulation.
A marker assumes the relevant audible phenotype. For example, an ejection click or opening snap assumes sufficiently mobile leaflets; severely calcified immobile valves may not produce that sound clinically.
S1 separates mitral and tricuspid closure by a short reference interval, widened in the selected RBBB example. S2 follows A2/P2 timing with ordinary inspiratory widening, wider splitting in selected RBBB/PS examples, and reversed/paradoxical ordering with delayed LV ejection in selected left-sided conduction/outflow states.
Large ASD has a fixed-splitting example; PAPVR alone does not inherit it. Pulmonary hypertension uses an accentuated P2 and a selected narrow split rather than assuming fixed splitting in every patient. Positive-pressure ventilation does not blindly apply spontaneous inspiratory rules.
The opening-snap delay uses LA pressure and LV systolic pressure: 0.15 − 0.004 × (LA pressure − 3) + 0.0002 × (LV systolic pressure − 120), bounded to 0.045–0.14 seconds. This is a synthetic timing relation, not a valve-area equation. Transmitted external pressure is excluded from its filling interpretation.
Ejection clicks track the relevant pressure-dependent opening event. The MVP click shifts with loading/prolapse factor rather than grade alone. Very short cardiac cycles compress some timing to fit available diastole; the tooltip identifies that limitation.
A congested selected myocardial/regurgitant phenotype can add S3. S4 requires an organized atrial contraction and a compatible stiff-ventricle phenotype, so AF does not receive a normal S4. Constriction can add an early diastolic knock. Marker presence and amplitude are teaching assumptions, not diagnostic sensitivity or specificity.
