Physical and physiologic determinants of pulmonary venous flow:
numerical analysis.
Thomas, James D., Jianhua Zhou, Neil Greenberg, George Bibawy, Patrick
M. McCarthy, Pieter M. Vandervoort.
Cardiovascular Imaging Center, Departments of Cardiology and
Cardiothoracic Surgery, The Cleveland Clinic Foundation, Cleveland,
Ohio
APStracts 3:0495H, 1996.
To study the physical and physiologic determinants of transmitral and
pulmonary venous flow, a lumped parameter model of the cardiovascular
system has been created, modeling the instantaneous pressure, volume,
and influx/efflux of the pulmonary veins, left atrium and ventricle,
systemic arteries and veins, right atrium and ventricle, and
pulmonary arteries. Initial validation has been obtained by direct
comparison with transesophageal echocardiographic recordings of
mitral and pulmonary venous velocity for the following clinical
situations: normal diastolic function, delayed ventricular
relaxation, restrictive filling due to severe systolic dysfunction,
severe mitral regurgitation before and after valve repair surgery,
and premature atrial contraction occurring during ventricular
systole. Sensitivity analysis has been performed with a Jacobian
matrix, representing the proportional change in a group of output
indices (yi) in response to isolated changes in input parameters
(xj), ((yi/yi)/(xj/xj)), demonstrating the complementary nature of
mitral and pulmonary venous A-wave velocity for predicting
ventricular stiffness and atrial systolic function. This unified
numerical/experimental programming environment should facilitate
model refinement and physiologic data exploration, in particular
guiding more accurate interpretations of Doppler echocardiographic
data.
Received 15 August 1995; accepted in final form 18 October 1996.
APS Manuscript Number H769-5.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 31 December 1996