Validation of New Pulsed Doppler Echocardiographic Techniques for Assessment of Pulmonary Hemodynamics

In preparation for a vasodilator study on chronic obstructive pulmonary disease (COPD), we investigated the reliability of recently described pulsed Doppler techniques for estimating pulmonary artery pressure (PAP) and cardiac output (CO). Our aims were to determine the following: (1) the imaging success rate for pulsed Doppler measurements; (2) the repeatability of the measurements, and interobserver and intraobserver variability; and (3) the accuracy of Doppler compared with catheter measurements. Doppler studies were attempted in 81 patients (cardiac diseases [23], COPD [22], sleep apnea [32], and normal subjects [4]). Suitable images were obtained in 68 subjects (84 percent) and in 76 subjects (94 percent) for PAP and CO estimations, respectively. The lowest imaging success rates were in COPD patients (68 percent for PAP and 86 percent for CO estimation). Repeatability of the techniques was assessed in four cardiac patients and three healthy volunteers by performing four replicate studies in each subject over 1 h. Intrasubject coefficient of variation was