Overview
Left Atrial Myxoma is selected under Valves → Mitral for its inflow consequences. It represents a pedunculated left atrial mass with intermittent obstruction, rather than fixed narrowing of the native mitral leaflets. Clinical findings can vary with mass mobility and body position; this example does not diagnose a mass or represent every myxoma.
A fixed eight-beat mobility pattern deliberately changes the selected obstructive state. The pattern is deterministic, so replay and paused inspection agree. It is not patient tracking, random instrument noise, a simulated posture change or a probability of obstruction or syncope.
Upstream pressure and ventricular filling
Inflow obstruction separates upstream atrial/wedge pressure from LV end-diastolic pressure. A raised wedge therefore does not require an equally raised LVEDP or primary LV contractile failure. Coexisting valve, myocardial, pericardial and vascular disease retain their own contributions.
The moving-mass helper supplies one shared per-beat state to the pressure, filling and visual layers. Its obstruction strengths, timing pattern and reference pressures are original educational choices. The output is not a fluid–structure calculation of tumor motion, a measured transmitral valve area or a reconstruction from imaging.
The displayed circulation solution and reference output describe the multi-beat mean. Representative obstructed beats have less ventricular filling and stroke-volume excursion while upstream atrial pressure rises. Both ventricular stroke volumes share the beat factor to preserve forward-volume consistency; this is a bounded response around the mean, without a fully transient atrial reservoir or a prediction of sustained complete occlusion.
The ordinary atrial contour is retained, with smooth mean-centered loading variation. A special pressure notch is not placed at a fixed phase to imitate tumor transit; the current model does not reproduce the detailed invasive atrial contour reported in individual clinical cases. Filling and the selected plop use the current modeled mitral-opening event.
Selected plop and inflow texture
The chosen audible phenotype adds an early-diastolic tumor plop as mass motion is checked after prolapse through the mitral orifice. The selected low-pitched damped sound differs from the brighter constrictive knock and mitral opening snap. Its pitch, gain and envelope are original sound design; the clinical plop is variable and occurs in only a minority of myxomas.
In Pitt and colleagues’ two surgically confirmed cases, early-diastolic mass transit caused a rapid atrial pressure descent despite severe inflow obstruction; the plop accompanied checking of tumor motion. That observation cautions against copying every fixed-mitral-stenosis atrial contour or interpreting the sound as valve opening itself. The small report does not define universal timing or a diagnostic waveform.
Treatment and interpretation limits
The schematic pedunculated mass is an authored illustration, not echocardiographic detection, histology or patient-specific anatomy. There is no tumor growth, embolization, constitutional-symptom or surgical-resection model. The mobility cycle does not predict sudden collapse or clinical risk.
Rate, loading and treatment can modify the shared circulation but do not remove the mass. A mitral clip, valvuloplasty or valve prosthesis does not cure this obstructive mechanism; a separately selected native valve lesion can still respond to its own procedure. The synthetic example is not a procedural recommendation or a validated treatment-response model.
References & further reading
