AJP - Heart and Circulatory Physiology, Vol 252, Issue 3 653-H665, Copyright © 1987 by American Physiological Society
Atrioventricular interactions: a theoretical simulation study
R. Beyar and S. Sideman
A quantitative model that describes the complex atrioventricular
interactions, based on the structure and myocardial properties of the left
atrium (LA) and left ventricle (LV), is presented. The description of the
LV follows our earlier study that assumes a nested-shell spheroidal
structure with fanlike fiber angle distribution, transmural electrical
activation velocity, and the muscle fiber dynamics with the classical
passive and active features of the sarcomeres. The LV model is extended
here to include an exponential load-dependent relaxation and viscous
(strain rate-dependent) features of the LV passive myocardium. The proposed
LA model is based on a thin-wall spherical geometry with a random fibrous
structure. The atrial muscle features differ from the ventricular muscle by
being much stiffer in the passive state and weaker but faster in the active
state. The LV and LA compartments are connected to a preload and afterload
scheme and interconnected by the mitral flow with its inertial properties.
The complex interactions between the LA and the LV are thoroughly studied
here, and the calculated results are consistent with well-established
experimental data.
