AJP - Regu AJP: Regulatory, Integrative and Comparative Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Regul Integr Comp Physiol 251: R627-R635, 1986;
0363-6119/86 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Beyar, R.
Right arrow Articles by Sideman, S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Beyar, R.
Right arrow Articles by Sideman, S.

AJP - Regulatory, Integrative and Comparative Physiology, Vol 251, Issue 3 627-R635, Copyright © 1986 by American Physiological Society

ARTICLES

Relating left ventricular dimension to maximum elastance by fiber mechanics

R. Beyar and S. Sideman

The dependence of the pressure-volume slope, which defines the maximum elastance (Emax) and the zero pressure-volume intercept (Vd) on the size and dimensions of the left ventricle (LV), is theoretically studied, and a normalizing parameter for Emax is suggested for normal and hypertrophied hearts. The study is based on our earlier model of the mechanics of the LV contraction, which assumes a nested-shell spheroidal shape, Streeter's fiber angle distribution, given stress-length and stress-strain rate functions of the sarcomeres, a radial propagation of the electrical activation front, and a windkessel arterial model. The study shows that Emax is linearly related to the maximum force that the optimal length sarcomeres can develop (sigma o), which is a characteristic measure of the contractility. Emax decreases and Vd increases with an increase in ventricular size, at a constant end-diastolic ratio (h/b)ed, where h is the wall thickness, and b is the semiminor axis of the prolate spheroidal LV. When the reference unstressed volume (V0) is held constant and the wall thickness increases, as in pure concentric hypertrophy, Emax decreases slightly and shifts to the left to a lower Vd value. In pure eccentric hypertrophy, wherein chamber size increases while the wall thickness remains constant, Emax decreases and Vd increases. A good index for myocardial function at constant configuration ratio (h/b)ed is obtained by multiplying Emax with the LV muscle volume (Vm). (h/b)ed is constant (= 0.45) for the normal heart but increases for concentric hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)


This article has been cited by other articles:


Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
T. E. Claessens, D. Georgakopoulos, M. Afanasyeva, S. J. Vermeersch, H. D. Millar, N. Stergiopulos, N. Westerhof, P. R. Verdonck, and P. Segers
Nonlinear isochrones in murine left ventricular pressure-volume loops: how well does the time-varying elastance concept hold?
Am J Physiol Heart Circ Physiol, April 1, 2006; 290(4): H1474 - H1483.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online