Overview
Catheter progression switches the pressure signal from RA to RV to PA to wedge along one shared pressure scale. The half-day teaching figure presents two cycles in each location as a continuous push-forward demonstration; its channel transitions are educational, not a catheter motion/position solver.
LV pullback samples LV, LVOT and aorta to distinguish a subvalvular dynamic gradient from a fixed valvular gradient. The tracing location changes while the simulated disease and underlying circulation remain selected.
Post-PVC response
The isolated provocation uses a baseline beat, a premature beat at 0.65 baseline cycles, a compensatory pause and a potentiated beat at cycle 2. The premature beat has reduced pressure/flow; the post-PVC LV peak rises.
Fixed AS increases the subsequent arterial pulse in this chosen example; HOCM can reduce arterial pulse pressure despite a larger LV pressure, illustrating the Brockenbrough–Braunwald–Morrow response. Mixed fixed/dynamic obstruction blends the response rather than switching HOCM off. This is a constructed provocation, not a measured post-extrasystolic contractility test.
Carabello demonstration
The optional severe-AS example adds a simultaneous femoral trace. While the catheter crosses the critically narrowed valve, an added obstruction reduces peripheral systolic pressure; withdrawal restores it. Transit delay and peripheral amplification are separate from the LV–aortic gradient.
The imposed obstruction is bounded and only available for the severe-AS/native-flow context. It illustrates the measurement pitfall; it does not estimate catheter size, actual valve area, embolic risk or procedural suitability.
Restriction and constriction comparison
The paused comparison uses simultaneous LV/RV and atrial signals plus respiratory context. It reports LVEDP–RVEDP, RVEDP/RVSP, PASP, rapid-filling pressure change and respiratory atrial/ventricular relationships. These criteria are complementary teaching clues, not individually diagnostic.
End-diastolic equalization and a dip-and-plateau can overlap. Respiratory discordance/interdependence versus concordance is more informative in the intended comparison. Ventilation, a large atrial communication and mixed disease can change the pattern, so interpretation must retain those assumptions.
References & further reading