AJP - Heart and Circulatory Physiology, Vol 257, Issue 3 1025-H1031, Copyright © 1989 by American Physiological Society
Left ventricular coordinate systems
G. H. Templeton, G. B. Seibert, M. Ramanathan, S. S. Cassidy and R. Johnson Jr
Pauline and Adolph Weinberger Laboratory for Cardiopulmonary Research, University of Texas Southwestern Medical Center, Dallas 75235-9040.
Three-dimensional kinematics of radiopaque markers in anterior, posterior,
septal, and lateral regions of a major equatorial plane were evaluated in
anesthetized dogs by biplane fluoroscopy. Stationary coordinate systems
measured marker locations recorded during diastole and systole from a
contractile origin at the center of contraction at end systole and from a
geometric origin at the intersection with the equatorial plane of the
ventricular long axis at end diastole. A time-indexed system measured
marker locations at end diastole and at end systole, respectively, from the
locations of the geometric origin at end diastole and end systole. Compared
to the stationary system with the geometric origin, both the stationary
system with the contractile origin and the time-indexed system reduced the
variability of the radial components of the contractile displacements
between ventricular regions. In contrast to the other two systems, the
system with the contractile origin reduced circumferential components to
values not significantly different from zero. These results indicate that
1) abnormally contracting regions of the ventricle may be located and their
size measured by determining the region where the radial component differs
from that in the rest of the equatorial plane and 2) rotation in a major
equatorial plane of the ventricle is significant, but the influence of
rotation can be minimized by referencing ventricular dimensions to a
coordinate system with an origin at the center of contraction.
