DOPPLER ESTIMATION OF PULMONARY-ARTERY SYSTOLIC PRESSURE REVISITED

Previous attempts at noninvasive estimation of pulmonary artery systol ic pressure (PA(S)) were limited by the inability to identify adequate spectral signals of tricuspid regurgitation (TR) in a significant pro portion of patients. Recently, image and color flow directed continuou s-wave Doppler have enabled spectral mapping of previously undetectabl e TR jets. Accordingly, 30 consecutive patients underwent two-dimensio nal and continuous-wave Doppler echocardiograms immediately before rig ht heart catheterization. PA(S) was calculated as SIGMA (4V2 + RA) whe re V is the maximal velocity of the TR jet in m/sec and RA is right at rial pressure as estimated by the caval respiratory index. Twenty-eigh t patients (93%) had detectable signals of TR. Directly measured PA(S) ranged from 21 to 95 mmHg (mean +/- SD, 40 +/- 18). Correlation betwe en Doppler and catheter-measured PA(S) was R - sq = 0.93 with a standa rd error of the estimate of 4.7 mmHg. Accurate results were obtained o ver a wide range of pulmonary pressures. Thus, noninvasive determinati on of PA(S) is feasible in most patients including those with normal P A(S), and correlates extremely well with direct measurements.