Comparative accuracy of Doppler echocardiographic methods for clinical stroke volume determination
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J Dubin1, D C Wallerson, R J Cody
1Division of Cardiology, New York Hospital-Cornell Medical Center, NY 10021.
Insights
Comparing Doppler echocardiography and thermodilution for stroke volume measurement, the aortic annular leading edge method demonstrated superior accuracy in patients. This Doppler technique is recommended for clinical application due to its precision in assessing cardiac output.
Area of Science:
- Cardiology
- Medical Imaging
- Hemodynamics
Background:
- Doppler echocardiography offers non-invasive stroke volume (SV) assessment, but accuracy varies.
- Invasive methods like thermodilution are reference standards, but carry risks.
- Comparative studies on Doppler SV accuracy against invasive standards are limited.
Purpose of the Study:
- To compare the accuracy of various Doppler echocardiographic methods for measuring stroke volume against thermodilution.
- To identify the most accurate and clinically applicable Doppler method for SV assessment.
Main Methods:
- Compared six Doppler echocardiographic methods against thermodilution in 18 hospitalized patients.
- Measured Doppler time-velocity integrals (TVIs) using darkest line and leading edge techniques.
- Utilized aortic annular and mitral orifice planes, with 2D echocardiography for cross-sectional areas.
Main Results:
- The combination of aortic annular cross-sectional area and the leading edge TVI technique showed the highest accuracy for SV (r=0.87).
- This method also provided the most accurate cardiac output measurements (r=0.88).
- Other Doppler methods exhibited lower correlation and systematic deviations from thermodilution.
Conclusions:
- The aortic annular leading edge Doppler method is the most accurate for measuring stroke volume among the evaluated techniques.
- This method is deemed most suitable for clinical application in patients.
- Accurate non-invasive SV assessment is crucial for managing cardiovascular conditions.
Abstract:
Numerous Doppler echocardiographic methods to measure stroke volume have been proposed in experimental or clinical studies, but their relative accuracy in patients compared with an invasive reference standard remains uncertain. Accordingly, we compared Doppler with thermodilution stroke volume measurement in 18 hospitalized patients, 16 with an acute manifestation of coronary artery disease and two with chronic cardiomyopathies. Doppler time-velocity integrals were measured by darkest line (modal velocity) and the leading edge (maximal velocity) techniques at the aortic annular plane, the mitral orifice, and the mitral annular plane. Two-dimensional echocardiography was used to measure cross-sectional areas (M-mode-corrected at the mitral orifice). The combination of aortic annular cross-sectional area and the leading edge technique of measuring the time-velocity integral of blood flow at this site provided the most accurate measure of stroke volume (r = 0.87, p less than 0.0001, standard error of estimate = 11 cm3; mean difference from thermodilution = 2.8 ml +/- 8.9 ml, p = NS). It also resulted in the most accurate measurement of cardiac output (r = 0.88, p less than 0.0003; mean difference from thermodilution = 0.11 L/min +/- 0.69 L/min, p = NS). Other methods yielded values that correlated less closely and deviated systematically from thermodilution measurements. We therefore conclude that of the six common methods evaluated, the aortic annular leading edge method measures stroke volume with the best accuracy and is most suitable for clinical application.