Correction of Doppler Gradients for Pressure Recovery Improves Agreement with Subsequent Catheterization Gradients in Congenital Aortic Stenosis

Temporal relationship between instantaneous pressure gradients and peak-to-peak systolic ejection gradient in congenital aortic stenosis

“…Beekman et al devised a model accounting for pulse pressure ( , r 2 = 0.97) to correlate these gradients which was verified by the Toronto group . More recent studies have demonstrated lesser correlations between these measured gradients in congenital aortic stenosis with slopes deviating from unity . Discrepancies between Doppler measurements of aortic valve gradients and catheterization measured PPSG have been attributed to four major factors: Angle and signal quality affecting the Doppler gradient measurement. The effect of pressure recovery as potential energy is converted into kinetic energy across a stenotic aortic valve.…”

“…These echocardiographic parameters can support a referral for cardiac catheterization, however, are not surrogates for the PPSG based on current guidelines . Several reports have demonstrated the inclusion of estimation of pressure recovery improves correlation of Doppler measured gradients to those at catheterization . Pressure recovery (PR) is calculated using the equation below ( v = velocity across the aortic valve, AVA = aortic valve area, AoA = cross sectional area of the aorta).…”

“…Many studies have attempted to correlate aortic valve maximal and mean IPG to PPSG with variable success. The maximum IPG often overestimates the PPSG while the mean IPG has been shown to underestimate the PPSG in congenital aortic stenosis with regression equations deviating significantly from identity . Mathematical models to calculate PPSG from echocardiographic measurements have been studied, but are not commonly used …”

Simplified Bernoulli's method significantly underestimates pulmonary transvalvular pressure drop

“…Quantitative assessment of the severity of pulmonary valve stenosis is mainly based on the pulmonary transvalvular pressure drop, commonly estimated by continuous‐wave Doppler and recently by magnetic resonance imaging (MRI) phase contrast flow measurements . The accuracy of noninvasive measurements of the transvalvular pressure drop has been debated . Several studies have investigated the correlation between MRI measurements and echocardiography with catheterization for the estimation of the pressure drop in pulmonary circulation.…”

Simplified Bernoulli's method significantly underestimates pulmonary transvalvular pressure drop

“…[4][5][6][7][8][9][10][11] Several studies have investigated the correlation between MRI measurements and echocardiography with catheterization for the estimation of the pressure drop in pulmonary circulation. The results have been inconsistent.…”