Inaccuracy of Doppler estimates of pulmonary artery pressure using pulmonary flow acceleration time

Pulsed Doppler echocardiography was used to estimate mean pulmonary artery pressure (PAP), mean pulmonary artery wedge pressure PAWP) and the changes in PAP and PAWP following intervention in an unselected population composed of 60 patients undergoing routine diagnostic cardiac catheterization. Simultaneous Doppler and strain gauge manometry recordings of PAP and PAWP were interpreted by independent observers in a blinded fashion. A first set of measurements was obtained before left ventricular angiography and a second soon after the injection of contrast dye. The mean Doppler PAP and PAWP were derived from acceleration time and calculated using previously published regression equations: PAP = -0.45 x AcT + 79, PAWP = 57 - 0.39 x AcT. At rest, PAP measurements by strain gauge manometry ranged from 13 to 45 mmHg with a mean of 24 +/- 10 (one standard deviation); PAWP ranged from 2 to 40 mmHg with a mean of 15 +/- 6. Following left ventricular angiography, the PAP ranged from 18 to 50 mmHg with a mean of 29 +/- 7; PAWP ranged from 6 to 45 mmHg with a mean of 20 +/- 7. The values obtained by pulsed Doppler before and after intervention correlated poorly with those obtained by strain gauge manometry (r = 0.09 and 0.26 for PAP; r = 0.03 and 0.25 for PAWP).(ABSTRACT TRUNCATED AT 250 WORDS)