Fiber stress profiles in the left ventricle of the heart during diastole: Effects of distension and hypertrophy |
| |
Authors: | P C Voukydis |
| |
Institution: | (1) Cardiac Unit, Beth Israel Hospital, Boston, Massachusetts |
| |
Abstract: | Pressure-volume and volume-dimensions relationships, obtained from excised dog left ventricles were used for calculating the
stresses acting along the longitudinal axis of the individual myocardial fibers. The calculations were based on a set of empirical
and theoretical equations. The pressure-volume relationship as well as the volume-dimensions relationships for the excised
left ventricle were expressed in the form of empirical equations; the fiber orientation was written as a function of the fiber
location within the left ventricular wall; finally, the fiber stress was determined by means of theoretically derived formulas.
Simultaneous solutions for the fibers of a meridian cut through the left ventricular myocardial shell were obtained by means
of a digital computer and presented in the form of diagrams. The results showed that at low degrees of distension of the left
ventricle there are two zones of higher stresses at the equatorial area, one near the epicardium and one near the endocardium.
As the distension proceeds under the effect of progressively increasing intraventricular pressure, these two zones become
less well defined, whereas a new zone of higher stresses appears near the apex. At high degrees of distension, the ventricle
assumes a more spherical shape and the equatorial zones of higher stresses are replaced by zones of lower stresses. Increase
in the myocardial mass results in appearance of the equatorial lower stress zones at lower degrees of distension. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|