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Doppler evaluation of aortic valve area in children with aortic stenosis
A R Bengur1, A R Snider, J N Meliones
1Department of Pediatrics, C.S. Mott Children's Hospital, University of Michigan Medical Center, Ann Arbor 48109-0204.
Insights
Doppler echocardiography accurately assesses aortic valve stenosis severity in children using the continuity equation. This method provides reliable aortic valve area measurements, aiding in clinical decisions for pediatric patients.
Area of Science:
- Pediatric Cardiology
- Echocardiography
- Valvular Heart Disease
Background:
- Aortic valve stenosis (AVS) severity assessment is crucial in pediatric patients.
- Hemodynamic evaluation often involves invasive cardiac catheterization.
- Non-invasive echocardiography offers a potential alternative for AVS assessment.
Purpose of the Study:
- To evaluate the utility of Doppler-derived aortic valve area (AVA) using the continuity equation.
- To assess the hemodynamic severity of AVS in infants and children.
- To compare Doppler-derived AVA with cardiac catheterization data.
Main Methods:
- Two-dimensional and Doppler echocardiography performed on 42 pediatric patients.
- Left ventricular outflow tract (LVOT) diameter measured from parasternal long-axis view.
- Flow velocities proximal and jet velocities across the aortic valve measured using pulsed and continuous wave Doppler.
Main Results:
- Doppler-derived AVA using velocity-time integral correlated well with mean (r=0.97) and peak (r=0.95) velocities.
- Mean Doppler AVA was 0.57 +/- 0.25 cm2/m2.
- Seventeen patients (all <= 6 years) had small LVOT diameters (< 1.4 cm) and areas (< 1.5 cm2).
Conclusions:
- Doppler echocardiography with the continuity equation is a useful method for assessing AVS hemodynamic severity in children.
- This non-invasive technique provides reliable AVA measurements, comparable to invasive methods.
- Findings support the use of Doppler echocardiography in managing pediatric AVS.
Abstract:
To evaluate the usefulness of the Doppler-derived aortic valve area calculated from the continuity equation in assessing the hemodynamic severity of aortic valve stenosis in infants and children, two-dimensional and Doppler echocardiographic examinations were performed on 42 patients (aged 1 day to 24 years) a median of 1 day before or after cardiac catheterization. The left ventricular outflow tract diameter was measured from the parasternal long-axis view at the base of the aortic cusps from inner edge to inner edge in early systole. The flow velocities proximal to the aortic valve were measured from the apical view with use of pulsed Doppler echocardiography; the jet velocities were recorded from the apical, right parasternal and suprasternal views by using continuous wave Doppler echocardiography. The velocity-time integral, mean velocity and peak velocity were measured by tracing the Doppler waveforms along their outermost margins. Seventeen patients (all less than or equal to 6 years old) had a very small left ventricular outflow tract diameter (less than or equal to 1.4 cm) and cross-sectional area (less than or equal to 1.5 cm2). The Doppler aortic valve area calculated with use of velocity-time integrals in the continuity equation (0.57 +/- 0.25 cm2/m2, mean value +/- SD) correlated well with the Doppler aortic valve area calculated by using mean (0.55 +/- 0.25 cm2/m2) and peak (0.54 +/- 0.24 cm2/m2) velocities, with correlations of r = 0.97 and 0.95, respectively. Thirty-four patients had sufficient catheterization data to calculate aortic valve area from the Gorlin formula.(ABSTRACT TRUNCATED AT 250 WORDS)