thesis
Quantification of cardiac blood flow by Doppler technique
- Publication date
- 18 December 1985
- Publisher
- The investigations described in this thesis started as part of the research program
of the divisions of pediatric cardiology of the Universities of Arizona and California
(San Diego). The investigations were part of an ongoing project designed by
D.J. Sahn and L.M. Valdes-Cruz.
This project was initiated to implement Doppler techniques in the daily practice of
pediatric cardiology. New developments in medical technology made the Doppler
techniques integrated into sophisticated two-dimensional echocardiographic
equipment available to the clinician. In order to extend the use of the Doppler
equipment beyond that of a sophisticated stethoscope and to enter the era of
quantitative two-dimensional Doppler echocardiography it was felt that clinical
validation of simple quantification approaches was necessary.
As an initial approach animal studies were performed. Open chest dog models
were created where simultaneously with the Doppler studies electromagnetic flow
measurements and pressure gradients could be obtained. The results of both
techniques were compared and a good correlation was obtained. Twodimensional
Doppler echocardiographic quantifications were subsequently performed
in patients with a variety of diseases during cardiac catheterization to
validate the results in a clinical setting.
The blood flow calculations over the mitral valve orifice and the development of
the mitral valve flow method, including the mean to maximal index of the mitral
valve, were performed by D. Fisher.
Measurement of shunt size at atrial and ventricular level of the left-to- right type
was validated by S. Horowitz. The measurement of extracardiac type left-to-right
shunting such as in the persistent ductus arteriosus, of the tricuspid valve flow and
a simplified approach to measurement of mitral valve flow will be described in this
thesis.
The tricuspid valve method and the simplified mitral valve methods are both
studied in patients during cardiac catheterization for validation purposes and were
subsequently used for calculation of flows in the human fetus during the second
and third trimester of pregnancies.
This thesis was completed by the study of the reproducibility of the previously
described techniques in human subjects. This part of the investigation was performed
at the Thoraxcenter in Rotterdam and supported by the Interuniversity
Cardiology Institute of the Netherlands. This investigation was supervised by
Professor Born and Professor Roeland!. H.Rijsterborgh performed the statistical
analysis