Errors in measurements of stroke volume for invasive and echo-Doppler evaluations of valvular regurgitant fractions. Clinical evaluation and computer simulation Intra-arterial blood pressure monitoring in the evaluation of the hypertensive athlete

Abstract

The aim of this study was to compare cardiac catheterization (CATH) with 2D echo-Doppler (ED) in clinically evaluating the stroke volumes (SV) needed to calculate aortic and mitral regurgitant fractions (aortic and mitral SV for the ED method, thermodilution and angiographic SV for the CATH). As there is no 'gold standard' for this kind of measurement, only subjects without valvular regurgitation were considered. In these subjects, though the two SV measurements needed to calculate the regurgitant volume should have been identical, there was, in fact a difference due to the systematic and random errors of the methods. We calculated the mean value and the standard deviation of this difference in a series of patients without valvular regurgitation in order to obtain an estimate of both systematic and random errors. In 20 patients studied by ED a difference of 11.9 +/- 16.7 ml was found. In 36 patients studied by cardiac catheterization the difference was 19.6 +/- 20.1 ml. A significant systematic error was found for both ED and the invasive method; The transmitral SV tended to be larger than the aortic and the angiographic SV larger than that obtained by thermodilution. To try to determine the extent to which the random errors could be attributed to the reproducibility of the measurements, we carried out computer simulations. The SVs of 50 000 hypothetical patients were randomly generated and then attributed a random error calculated on the basis of the variability of the CATH (thermodilution 4%, angiography 10%) and the ED measurements (aortic annulus 6%, mitral annulus 18%, mitral time velocity integral 10%, aortic time velocity integral 8%).(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitation of valve regurgitation severity by three‐dimensional vena contracta area is superior to flow convergence method of quantitation on transesophageal echocardiography

“…Conversely, PISA overestimates regurgitation due to mitral valve prolapse and nonoptimal flow convergence . The volumetric Doppler method for MR suffers from geometrical assumptions, measurement variability, and requisite lack of important aortic insufficiency …”

“…3 The volumetric Doppler method for MR suffers from geometrical assumptions, measurement variability, and requisite lack of important aortic insufficiency. 4 2D PISA quantitation affects clinical outcome for MR, 5,6 tricuspid regurgitation (TR), 7 aortic regurgitation (AR), 8,9 and prosthetic perivalvular regurgitation. 10 Limitations of the 2D PISA method include assessment in a single anatomic plane, nonhemispheric isovelocity shells, asymmetric or eccentric flow convergence, suboptimal convergence and interrogation window, 8 and changes in PISA radius throughout systole 11,12 for MR, and presence of multiple regurgitant jets.…”

A comparison of left ventricular volumes and regurgitant fraction by Doppler echocardiography and angiography in children

“…In a beat to beat simultaneous echoventriculographic study done by graphic and angiographic methods had significant systematic errors in calculating the stroke volume, such that the trans-mitral echocardiographic stroke volume tended to be larger than the aortic and the angiographic stroke volume tended to be larger than that obtained by the thermodilution m e t h~d .~ Random errors on the basis of catheterization and echocardiographic measurements are attnibuted to the thermodilution technique by 4%, to angiography by 1 O%, to the measurement of the aortic annulus by 6% and to the aortic velocity time integral by 8%. 4 It is reported that the difference between total left ventricular stroke volume from biplane angiograms and forward stroke volume by the Fick method is often off by 20%.334 Although we have shown a consistent underestimation of left ventricular volumes and the regurgitant fraction by echocardiography when compared to cardiac catheterization, we feel that careful methodology should allow a reliable measurement for the serial evaluation and management of the individual patient.…”