|
|
||||||||
AJP - Heart and Circulatory Physiology, Vol 257, Issue 6 1927-H1935, Copyright © 1989 by American Physiological Society
ARTICLES |
T. C. Gillebert and W. Y. Lew
Department of Medicine, Veterans Administration Medical Center; San Diego, California 92161.
We examined the influence of loading conditions and nonuniformity of left ventricular (LV) function on the rate of LV pressure fall in seven anesthetized dogs. Loading conditions were altered with vena cavae occlusions and/or intravenous infusions of dextran. Nonuniformity was produced by injecting 8-20 ng of isoproterenol into the mild left anterior descending coronary artery to produce an asynchronous and early onset of segment lengthening in the anterior wall. Temporal and regional nonuniformity were quantified with indexes derived by comparing segment lengths in the anterior and posterior walls, measured with midwall sonomicrometers. The rate of LV pressure fall was assessed with peak -dP/dt, the time constant, tau, and the duration of isovolumic relaxation. Volume loading decreased the rate of LV pressure fall without altering the nonuniformity indexes. Intracoronary isoproterenol produced nonuniformity and decreased the rate of LV pressure fall without altering global loading conditions. The effects of isoproterenol (in a constant dose) were similar irrespective of the LV volume. We conclude that in the intact, ejecting left ventricle, loading conditions and nonuniformity are important determinants of the rate of LV pressure fall, but these two factors exert their influence by mechanisms that are largely independent.
This article has been cited by other articles:
![]() |
S F De Marchi, Y Allemann, and C Seiler Relaxation in hypertrophic cardiomyopathy and hypertensive heart disease: relations between hypertrophy and diastolic function Heart, June 1, 2000; 83(6): 678 - 684. [Abstract] [Full Text] |
||||
![]() |
D. Fan, L. K. Soei, R. Stubenitsky, E. Boersma, D. J. Duncker, P. D. Verdouw, and R. Krams Contribution of asynchrony and nonuniformity to mechanical interaction in normal and stunned myocardium Am J Physiol Heart Circ Physiol, November 1, 1997; 273(5): H2146 - H2154. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Teramura, T. Yamakado, M. Maeda, and T. Nakano Effects of MCI-154, a Calcium Sensitizer, on Left Ventricular Systolic and Diastolic Function in Pacing-Induced Heart Failure in the Dog Circulation, February 4, 1997; 95(3): 732 - 739. [Abstract] [Full Text] |
||||
![]() |
H. Kondo, T. Masuyama, K. Ishihara, T. Mano, K. Yamamoto, J. Naito, R. Nagano, S. Kishimoto, J. Tanouchi, M. Hori, et al. Digital Subtraction High-Frame-Rate Echocardiography in Detecting Delayed Onset of Regional Left Ventricular Relaxation in Ischemic Heart Disease Circulation, January 15, 1995; 91(2): 304 - 312. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |