Doppler Estimation of Pulmonary Artery Systolic Pressure Revisited

Previous attempts at noninvasive estimation of pulmonary artery systolic pressure (PA S ) were limited by the inability to identify adequate spectral signals of tricuspid regurgitation (TR) in a significant proportion of patients. Recently, image and color flow directed continuous‐wave Doppler have enabled spectral mapping of previously undetectable TR jets. Accordingly, 30 consecutive patients underwent two‐dimensional and continuous‐wave Doppler echocardiograms immediately before right heart catheterization. PA S was calculated as ∑ (4V 2 + RA) where Vis the maximal velocity of the TR jet in ml sec and RA is right atrial pressure as estimated by the caval respiratory index. Twenty‐eight patients (93%) had detectable signals of TR. Directly measured PA S ranged from 21 to 95 mmHg (mean ± SD, 40 ± 18). Correlation between Doppler and catheter‐measured PA S was R‐sq = 0.93 with a standard error of the estimate of 4.7 mmHg. Accurate results were obtained over a wide range of pulmonary pressures. Thus, noninvasive determination of PA S is feasible in most patients including those with normal PA S , and correlates extremely well with direct measurements.