Linked Life Data

20400687

Source:http://linkedlifedata.com/resource/pubmed/id/20400687

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2010-5-20
pubmed:abstractText
Anterior mitral leaflet stiffness during isovolumic contraction (IVC) is much greater than that during isovolumic relaxation (IVR). We have hypothesized that this stiffening is due to transient early systolic force development in the slip of cardiac myocytes in the annular third of the anterior leaflet. Because the atrium is excited before IVC and leaflet myocytes contract for < or = 250 ms, this hypothesis predicts that IVC leaflet stiffness will drop to near-IVR values in the latter half of ventricular systole. We tested this prediction using radiopaque markers and inverse finite element analysis of 30 beats in 10 ovine hearts. For each beat, circumferential (E(c)) and radial (E(r)) stiffness was determined during IVC (Deltat(1)), end IVC to midsystole (Deltat(2)), midsystole to IVR onset (Deltat(3)), and IVR (Deltat(4)). Group mean stiffness (E(c) + or - SD; E(r) + or - SD; in N/mm(2)) during Deltat(1) (44 + or - 16; 15 + or - 4) was 1.6-1.7 times that during Deltat(4) (28 + or - 11; 9 + or - 3); Deltat(2) stiffness (39 + or - 15; 14 + or - 4) was 1.3-1.5 times that of Deltat(4), but Deltat(3) stiffness (32 + or - 12; 11 + or - 3) was only 1.1-1.2 times that of Deltat(4). The stiffness drop during Deltat(3) supports the hypothesis that anterior leaflet stiffening during IVC arises primarily from transient force development in leaflet cardiac myocytes, with stiffness reduced as this leaflet muscle relaxes in the latter half of ventricular systole.
pubmed:grant
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1522-1539
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
298
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H2221-5
pubmed:dateRevised
2011-7-28
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Transient stiffening of mitral valve leaflets in the beating heart.
pubmed:affiliation
Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, CA, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural