[Two-dimensional pulsed Doppler echocardiographic estimates of cardiac output in man: sampling at the entrance to the main pulmonary artery].
To assess the feasibility and accuracy of measuring cardiac outputs (CO) by two-dimensional (2-D) pulsed Doppler echocardiography, taking samples at the main pulmonary artery just beyond the pulmonary valve, 62 cardiac patients were studied. The results obtained were compared with CO values determined by the thermodilution technique. 2-D Doppler echocardiograms suitable for computing CO were recorded in 37 (60%) of 62 patients. A significant correlation (r = 0.64) was observed between 2-D echocardiographic and angiographic pulmonary ring diameters (PRD), but the echocardiographic PRD was smaller than that of angiography by 0.4 +/- 0.2 cm. Thus, to compute the Doppler CO, the echocardiographic PRD had to be corrected by the difference between the angiographic and echocardiographic PRD. The angle between the ultrasound beam and the pulmonary blood flow was 7.8 +/- 6.1 degrees (0 approximately 18 degrees), and this was negligible for computing the Doppler CO. Even in cases with atrial fibrillation, the Doppler CO could be computed as is done in sinus rhythm. The correlation between the thermodilution and Doppler CO was highly significant (r = 0.92), and the regression equation was as follows: Thermodilution CO = 1.09 X (Doppler CO)-0.19 The difference between thermodilution and Doppler CO was 3.4 +/- 10.0% (-21 approximately +21%). Comparing the differences in CO between the thermodilution and dye-dilution techniques, those between thermodilution and the Fick methods, and those among thermodilution methods reported in the literatures, the difference in this study was not large and was acceptable. Thus, measurement of CO by pulsed Doppler echocardiography, with sampling entrance to the main pulmonary artery, can be used clinically.
D000328:Adult; D002302:Cardiac Output; D004452:Echocardiography; D005260:Female; D006331:Heart Diseases / Q000503:physiopathology; D006801:Humans; D008297:Male; D008722:Methods; D008875:Middle Aged; D013815:Thermodilution