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Doppler echocardiographic comparison of flows distal to the four cardiac valves
Insights
Doppler echocardiography accurately measures cardiac flows in the ascending aorta, pulmonary artery, and tricuspid valve. Mitral valve flow measurements showed more variability in this study of normal subjects.
Area of Science:
- Cardiovascular Physiology
- Medical Imaging
- Echocardiography
Background:
- Doppler and invasive methods for cardiac flow measurement show good correlation.
- Previous studies have not correlated Doppler-derived flows distal to all four cardiac valves within the same individuals.
Purpose of the Study:
- To measure and correlate four cardiac flows (ascending aorta, main pulmonary artery, tricuspid inflow, and mitral inflow) in normal subjects using range-gated pulsed Doppler echocardiography.
Main Methods:
- Utilized range-gated pulsed Doppler echocardiography in 22 normal subjects (ages 4-29).
- Measured velocities at a near 0-degree beam-flow intercept angle.
- Determined vessel and orifice dimensions using 2D echocardiography.
Main Results:
- Flows in the ascending aorta, main pulmonary artery, and tricuspid valve inflow areas were similar in magnitude and strongly correlated (r=0.93-0.98).
- Mitral valve flows exhibited high variability and weaker correlation (r=0.59-0.67) with other measured flows.
- Accurate velocity angle and precise diameter measurements significantly improved correlation for aorta, pulmonary artery, and tricuspid flows.
Conclusions:
- Range-gated pulsed Doppler echocardiography provides reliable flow measurements for the aorta, pulmonary artery, and tricuspid valve in normal individuals.
- Mitral valve flow assessment may require different methodologies due to observed variability.
- Optimized Doppler techniques, including angle verification and accurate dimensioning, enhance the reliability of cardiac flow quantification.
Abstract:
Cardiac flows measured by the Doppler technique and invasive methods correlate well, but no prior study has correlated Doppler flows obtained distal to the four cardiac valves in the same individual. The purpose of this investigation was to measure the four flows in normal subjects using the range-gated pulsed Doppler echocardiographic technique. Velocities were obtained from 22 subjects aged 4 to 29 years at a beam-flow intercept angle close to 0 degree in the ascending aorta, distal main pulmonary artery and the tricuspid and mitral valve outflow areas. Vessel and orifice sizes of the ascending aorta, main pulmonary artery and tricuspid valve orifice were measured directly from two-dimensional echocardiographic images. The mitral valve orifice was measured by a previously described method. Results show that flow values for the ascending aorta, main pulmonary artery and tricuspid valve inflow area were similar in absolute magnitude and correlated strongly (r = 0.93 to 0.98). Slopes for these relations were approximated at 1.0. The absolute magnitude of mitral valve flows was highly variable and showed the poorest correlation with flows from the other areas (r = 0.59 to 0.67). The high correlation of ascending aorta, main pulmonary artery and tricuspid valve outflow areas was considerably assisted by recording of velocity at a verified angle near 0 degree and obtaining accurate vessel and valve diameters. Improved angle accuracy was possible in the ascending aorta with the use of a new transducer designed to image anteroinferiorly from the suprasternal notch. A relatively simple method for measuring tricuspid flow was developed.(ABSTRACT TRUNCATED AT 250 WORDS)