AJP - Heart and Circulatory Physiology, Vol 266, Issue 6 2380-H2387, Copyright © 1994 by American Physiological Society
Inward diastolic motion: a normal component of isovolumic relaxation and rapid refill
J. J. McInerney, R. D. Aronoff, S. H. Blasko, G. L. Copenhaver and M. D. Herr
Department of Medicine, Pennsylvania State University, Hershey.
Many reports note expansive events occurring in the left ventricle during
isovolumic relaxation. Expansions during isovolumic relaxation require
compensatory inward displacements elsewhere in the ventricle. The location
and character of such compensatory displacements have been a continuing
source of speculation. Using a high-precision Compton backscatter imaging
(CBI) technique, we have detected an early diastolic inward motion that
initiates during isovolumic relaxation on the right and left epicardial
free walls of the heart in 100% of the 14 normal canines we have studied.
This inward motion is first detected 20-30 ms after left ventricular
maximal rate of pressure decrease over time (-dP/dtmax), lasts into the
early rapid filling phase with a mean duration of 92 +/- 5 (SE) ms, and
ends approximately 30 ms after opening of the mitral valve. Maximum wall
velocities during this time period (approximately 20 mm/s) exceed those
occurring in the same regions during systole. Inward surface displacements
in the areas undergoing inward motion average 1.1 +/- 0.2 and 0.9 +/- 0.2
mm on the left and right side of the heart, respectively.
