Document Detail


Dynamic elasticity of human mitral valve chorade tendinease.
MedLine Citation:
PMID:  884599     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Chordae tendineae are under constant dynamic stress and, therefore, measurements of static properties alone cannot provide a complete analysis of their mechanical response under stress. This study investigated the dynamic viscoelastic properties of human mitral valve chordae tendineae. The tissue was subjected to sinusoidal strain variations over a frequency range of 0.42 to 6.68 Hz. At a fixed strain, the storage modulus, E', was found to be independent of applied frequency but varied inversely with chordal thickness. Values in the order of 10(8) dyn cm-2 (1 dyn=10 muN) were found. E' also increased with strain level. The phase lag, phi, between stressing function and response was found to be small (0.2-0.058 rad) and decreased with frequency. Values of phi at each frequency were found to be independent of chordal size and strain level. This property would enable a smooth and even closure of the valve and provide a more rapid response at elevated heart rates. The loss modulus, E'', was found to be 18 to 50 times smaller than E'. This implied an almost complete recovery on removal of any stress on the tissue. E'', which also decreased with frequency, was found to be smaller for the larger chordae.
Authors:
K O Lim; D R Boughner; C A Smith
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Publication Detail:
Type:  In Vitro; Journal Article    
Journal Detail:
Title:  Canadian journal of physiology and pharmacology     Volume:  55     ISSN:  0008-4212     ISO Abbreviation:  Can. J. Physiol. Pharmacol.     Publication Date:  1977 Jun 
Date Detail:
Created Date:  1977-09-29     Completed Date:  1977-09-29     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0372712     Medline TA:  Can J Physiol Pharmacol     Country:  CANADA    
Other Details:
Languages:  eng     Pagination:  413-8     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Adult
Aged
Biophysics / instrumentation
Chordae Tendineae / physiology*
Elasticity
Female
Humans
Male
Middle Aged
Mitral Valve / physiology*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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