Can the technique for Doppler estimate of pulmonary stenosis gradient be simplified?

Although Doppler echocardiography has been demonstrated to accurately predict the pressure drop across the pulmonary valve in patients with pulmonary valve stenosis, prior reports have stressed the need to correct for beam-flow intercept angles, to use simultaneous imaging, and to utilize the subcostal approach. The purpose of this study was to determine the accuracy of estimating the pressure drop in pulmonary stenosis patients by means of nonimaging Doppler applied without angle correction from precordial examination. Pressure drop estimated by Doppler was compared to that measured by strain gauge manometry at catheterization. Data for 39 patients (21 simultaneous measurements; 18 nonsimultaneous) were evaluated. Results for the entire group showed a good correlation (r = 0.94; SEE = 7.9 mm Hg). The correlation for simultaneous measurement improved somewhat (r = 0.95; SEE = 5.9), but the difference was not significant. Comparison of the slope and intercept of data of this study to those of prior studies, which advocated more complex methodology, indicated that results were essentially similar and that use of the additional steps did not confer a significantly improved result. We conclude that the simplified methodology utilized in this study provides accurate Doppler estimates of pressure gradient in patients with pulmonary stenosis.