Pressure recovery distal to a stenosis: Potential cause of gradient “verestimation” by Doppler echocardiography

Key Result

In vitro models demonstrate that pressure recovery distal to a stenosis can cause apparent Doppler overestimation of pressure gradients compared to downstream catheter measurements.

Key Points

• To determine whether poststenotic pressure recovery accounts for discrepancies between Doppler-derived and invasive catheter-measured intracardiac pressure gradients.
• Simulated poststenotic flow dynamics using in vitro models representing central stenoses and streamlined obstruction geometries modeled after hypertrophic cardiomyopathy.
• Evaluated velocity reduction, jet expansion, and downstream pressure recovery relative to the vena contracta under physiologic flow rates.
• Downstream expansion and deceleration of the poststenotic jet recovered pressure, leading to significantly lower invasive gradient measurements when catheters were placed distal to the vena contracta.
• Pressure recovery effects were most pronounced in streamlined tunnel geometries but remained clinically meaningful in central stenoses at physiologic flow rates.
• Doppler echocardiography accurately detected the maximal pressure gradient at the vena contracta, which governs the true hemodynamic load on the upstream chamber.