A comprehensive model for right-left heart interaction under the
influence of pericardium, intrathoracic pressure, and baroreflex.
Sun, Ying, Mazen Beshara, Richard J. Lucariello, and Salvatore A.
Chiaramida.
Department of Electrical and Computer Engineering, University of
Rhode Island, Kingston, Rhode Island 02881 and Division of
Cardiology, Our Lady of Mercy Medical Center, Bronx, New York
10466
APStracts 3:0435H, 1996.
A phenomenologic model of the cardiopulmonary circulation is developed
with a focus on the interaction between right heart and left heart.
The model predicts the hemodynamic consequences of changing
circulatory parameters in terms of a broad spectrum of pressure and
flow waveforms. Hemodynamics is characterized by use of an electrical
analogue incorporating mechanisms for transseptal pressure coupling,
pericardial volume coupling, intrathoracic pressure, and baroreflex
control of heart rate. Computer simulations are accomplished by
numerically integrating 28 differential equations that contain
nonlinear and time-varying coefficients. Validity of the model is
supported by its accurate fit to clinical pressure and Doppler
echocardiographic recordings. The model characterizes the hemodynamic
waveforms for mitral stenosis, mitral regurgitation, left heart
failure, right heart failure, cardiac tamponade, pulsus paradoxus,
and Valsalva maneuver. The wave shapes of pulmonary capillary wedge
pressure under the above conditions are also accurately represented.
Sensitivity analysis reveals that simulated hemodynamics is
insensitive to most individual model parameters with the exception of
afterload resistance, preload capacitances, intrathoracic pressure,
contractility, and pericardial fluid volume. Baseline hemodynamics is
minimally affected by transseptal coupling (up to 2%) and
significantly affected by pericardial coupling (up to 20%). The model
should be useful for quantitative studies of cardiopulmonary dynamics
related to right-left heart interaction under normal and diseased
conditions.
Received 22 January 1996; accepted in final form 12 September
1996.
APS Manuscript Number H87-6.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996