Journal of Ultrasound in Medicine, Vol 20, Issue 4 365-370, Copyright © 2001 by American Institute of Ultrasound in Medicine
Cardiac output measurements in congenital heart disease: validation of a simple, portable Doppler method
T. L. Gentles, J. M. Neutze, A. L. Caulder and E. R. Greene
Department of Cardiology, Green Lane Hospital, Auckland, New Zealand.
Noninvasive Doppler cardiac output measurements are clinical standards in
adults and children. Presently, these standard Doppler methods generally
require relatively expensive and large imaging equipment with complex
signal-processing techniques. Thus, universal access to these important
measurements has been limited. Simple, portable Doppler methods have been
validated previously and applied to infants and children without cardiac
disease. Nevertheless, these specific, inexpensive techniques have not been
validated in children with complex congenital heart disease. Accordingly,
we compared a noninvasive, suprasternal, non-image-guided, pulsed Doppler
cardiac output with standard invasive Fick cardiac outputs in 20 patients
(age range, 1 month to 15 years) with congenital heart disease. Doppler
cardiac output was displayed by multiplying the mean velocity with an
operator-selected angiographic or echographic estimate of the aortic
diameter. The values from linear regression analysis were r = 0.96; Doppler
cardiac output = 0.98 x Fick cardiac output - 0.08 L/min (range, 0.55-3.10
L/min). The 95% confidence limits were less than 35% of the mean of Doppler
and Fick cardiac outputs across the range of measurements. We conclude that
relatively linear and accurate measurements of cardiac output can be made
by this simple, inexpensive, portable method in selected infants and
children with various forms of congenital heart disease.
