|
|
||||||||
1 Department of Cardiovascular Dynamics, National Cardiovascular Center Research Institute, Suita, Osaka 565, Japan; and 2 Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee 37235
We developed a new technique to evaluate regional myocardial elastance using minute vibration. In 13 isolated cross-circulated canine hearts, we applied small sinusoidal vibrations of displacement to the left ventricular surface at various frequencies (50-100 Hz). Using the measured displacement and force between the vibrator head and myocardium, we derived myocardial elastance on the basis of the equation of motion for a given moment of the cardiac cycle. Simultaneous solution of the equations of motion at different frequencies yielded a unique value of elastance. Time-varying myocardial elastance increased from diastole (0.028 ± 0.211 × 106 dyn/cm) to systole (0.833 ± 0.391 × 106 dyn/cm). The end-systolic elastance (ees) linearly correlated with end-systolic left ventricular elastance (r = 0.717, P < 0.001) and also with the end-systolic Young's modulus (r = 0.874, P < 0.0001). We also measured ees at both ischemic and nonischemic regions during coronary occlusion. Young's modulus, estimated by normalizing ees by the wall thickness and by the estimated mass, did not change significantly at the nonischemic regions, whereas it decreased significantly from 2.303 ± 0.556 to 1.173 ± 0.370 × 106 dyn/cm2 at the ischemic region after coronary occlusion (P < 0.005). We conclude that this technique is useful for the quantitative assessment of regional myocardial elastance.
cardiac mechanics; myocardial contractility; muscle properties; stress-strain relationship; regional ischemia
This article has been cited by other articles:
![]() |
M. M. Riordan and S. J. Kovacs Stiffness- and relaxation-based quantitation of radial left ventricular oscillations: elucidation of regional diastolic function mechanisms J Appl Physiol, May 1, 2007; 102(5): 1862 - 1870. [Abstract] [Full Text] [PDF] |
||||
![]() |
Z. B. Popovic', K. A. Mowrey, Y. Zhang, S. Zhuang, T. Tabata, D. W. Wallick, R. A. Grimm, J. D. Thomas, and T. N. Mazgalev Slow rate during AF improves ventricular performance by reducing sensitivity to cycle length irregularity Am J Physiol Heart Circ Physiol, December 1, 2002; 283(6): H2706 - H2713. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Wronski, P. B. Persson, E. Seeliger, A. Harnath, and B. Flemming Coupling of left ventricular and aortic volume elasticity in the rabbit Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2000; 279(2): R539 - R547. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Shishido, M. Sugimachi, O. Kawaguchi, H. Miyano, T. Kawada, W. Matsuura, Y. Ikeda, and K. Sunagawa Novel method to estimate ventricular contractility using intraventricular pulse wave velocity Am J Physiol Heart Circ Physiol, December 1, 1999; 277(6): H2409 - H2415. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |