Author + information
- Received July 20, 1983
- Revision received October 21, 1983
- Accepted October 28, 1983
- Published online April 1, 1984.
- Gregory L. Johnson, MD, FACCa,
- Oi Ling Kwan, BS,
- Sharon Handshoe,
- Jacqueline A. Noonan, MD, FACC and
- Anthony N. DeMaria, MD, FACC
- ↵aAddress for reprints: Gregory L. Johnson, MD, Department of Pediatrics, University of Kentucky Medical Center, 800 Rose Street, Lexington, Kentucky 40536-0084.
Fifteen patients (median age 8.5 years) with fixed right ventricular outflow tract obstruction were evaluated by two-dimensional echocardiographically directed continuous wave Doppler ultrasound within 24 hours of cardiac catheterization. Pulmonary artery blood velocity measurements were determined from a real time spectral display of pulmonary artery flow profile and converted to pressure drop utilizing a modified Bernoulli equation. Use of both parasternal and subcostal imaging permitted more accurate detection of maximal flow velocity than did use of either approach alone. Gradients estimated from Doppler recordings correlated well with those measured at cardiac catheterization (correlation coefficient= 0.95, standard error of the estimate = 7.9 mm Hg) with a trend to slight underestimation of gradient in more severe obstruction. In three patients with combined valvular and subvalvular stenosis and one patient with right ventricular outlet obstruction due totally to a ventricular septal aneurysm, Doppler estimation of gradient provided an accurate assessment of total right ventricular-pulmonary artery gradient. Thus, continuous wave Doppler ultrasound combined with two-dimensional echocardiography provides a reliable noninvasive method of estimating pressure gradient in patients with right ventricular outflow tract obstruction.
This work was supported in part by a grant from the American Heart Association, Kentucky Affiliate, Louisville, Kentucky.
- Received July 20, 1983.
- Revision received October 21, 1983.
- Accepted October 28, 1983.
- American College of Cardiology Foundation