Objectives: The purpose of this study was to determine
whether Doppler echocardiographic assessment of right ventricular
pressure at the time of pulmonary valve opening could predict pulmonary
artery diastolic pressure.
echocardiography has been used to estimate right ventricular systolic
pressure noninvasively. Because right ventricular and pulmonary artery
diastolic pressure are equal at the time of pulmonary valve opening,
Doppler echocardiographic estimation of right ventricular pressure at
this point might provide an estimate of pulmonary artery diastolic
Methods: We studied 31 patients who
underwent right heart catheterization and had tricuspid regurgitation.
Pulmonary flow velocity was recorded by pulsed wave Doppler
echocardiography, and tricuspid regurgitant velocity was recorded by
continuous wave Doppler echocardiography. The time of pulmonary valve
opening was determined as the onset of systolic flow in the pulmonary
artery. Tricuspid velocity at the time of pulmonary valve opening was
measured by superimposing the interval between the onset of the QRS
complex on the ECG and the onset of pulmonary flow on the tricuspid
regurgitant envelope. The tricuspid gradient at this instant was
calculated from the measured tricuspid velocity using the Bernoulli
equation. This gradient was compared to the pulmonary artery diastolic
pressure obtained by right heart catheterization.
Measurements and results: The pressure gradient between the
right atrium and right ventricle obtained at the time of pulmonary
valve opening ranged from 9 to 31 mm Hg (mean, 19 ± 5) and
correlated closely with invasively measured pulmonary artery diastolic
pressure (range, 9 to 36 mm Hg; mean, 21 ± 7 mm Hg; r = 0.92; SEE,
1.9 mm Hg).
Conclusion: Doppler echocardiographic
measurement of right ventricular pressure at the time of pulmonary
valve opening is a reliable noninvasive method for estimating pulmonary