To compare left ventricular filling variables as derived by transmitral pulsed Doppler echocardiography (tpDE) and hemodynamic variables as assessed at right heart catheterization (RHC), 104 ICU patients (64 male, 40 female) aged 26 to 73 yr (mean 54.6 +/- 10.3) without valvular heart disease were examined. Simultaneously with RHC, transmitral flow velocity profiles were obtained by tpDE, and the ratio of the velocity-time integrals of late diastolic active (A wave) and early diastolic passive inflow into the left ventricle (E wave) was calculated (A/E ratio). Invasively determined pulmonary capillary wedge pressure (WP) ranged from 3 to 36 mm Hg (median 13.35, 5%/95% 6/31 mm Hg). Linear regression analysis showed a highly significant correlation between the A/E ratio and WP (r = .98, p less than .001, standard error of the estimate [SEE] = 0.10). The A/E ratio also correlated with other hemodynamic variables such as cardiac output (r = -.68, p less than .001, SEE = 0.33), cardiac index (r = -.74, p less than .001, SEE = 0.31), and stroke volume index (r = -.68, p less than .001, SEE = 0.34). The interobserver agreement (derived by intraclass correlation analysis between two examiners) on the A/E ratio was high (r = .95, p less than .001, n = 26). We conclude that WP can be accurately determined noninvasively by tpDE. For the assessment of systolic ventricular function, tpDE is of limited diagnostic value.