A hemodynamic analysis of coronary capillary blood flow based on
anatomical and distensibility data.
Kassab, Ghassan S., Kha N. Le, and Yuan-Cheng B. Fung.
Department of Bioengineering, University of California, San Diego,
La Jolla, CA 92093-0412
APStracts 6:0384H, 1999.
An understanding of cardiac health and disease requires knowledge of
the various factors that control coronary capillary blood flow. An
analysis of coronary capillary blood flow based on a complete set of
actual data on the capillary anatomy and elasticity does not exist.
Previously, a complete set of data on the branching pattern and the
vascular geometry of the pig's coronary capillary network were
obtained in our laboratory. In the present study, we have obtained
distensibility data on the coronary capillary blood vessels on the
epicardial surface using intravital microscopy in the form of
pressure-diameter relationship. A mathematical model of the coronary
capillary blood flow was then constructed on the basis of measured
anatomical and elasticity data of the coronary capillary network,
rheology of blood, the physical laws governing blood flow, and the
appropriate boundary conditions. The constructed model has been used
to examine the heterogeneity of the spatial distribution of coronary
blood flow which is an important issue in coronary physiology. One
interesting result of the model is that the dispersions of pressure
and flow are significantly reduced in the presence of capillary
cross-connections (Ccc), and the resistance to flow is reduced as
well. Finally, we have found that the compliance of the epicardial
surface capillary vessels is so small that its effect on the blood
pressure drop is negligible in the diastolic state. However, the
compliance of the intramyocardial capillaries remains unknown, and
the interaction of the muscle contraction and blood vessel elasticity
in systole remains to be studied.
Received 18 February 1999; accepted in final form 30 June 1999.
APS Manuscript Number H159-9.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1999 The American Physiological Society.
Published in APStracts on 9 July 1999