TY - JOUR
T1 - Characterization of biomechanical properties of aged human and ovine mitral valve chordae tendineae
AU - Zuo, Keping
AU - Pham, Thuy
AU - Li, Kewei
AU - Martin, Caitlin
AU - He, Zhaoming
AU - Sun, Wei
N1 - Funding Information:
This work was supported in part by the American Heart Association SDG Grant no. 0930319N and a NIH NRSA Individual pre-doctoral fellowship HL097722-01 . We would like to thank Kaitlyn Clarke and Stephen Pfohl for experimental and data analysis supports.
Publisher Copyright:
© 2016 Elsevier Ltd.
PY - 2016/9/1
Y1 - 2016/9/1
N2 - The mitral valve (MV) is a highly complex cardiac valve consisting of an annulus, anterior and posterior leaflets, chordae tendineae (chords) and two papillary muscles. The chordae tendineae mechanics play a pivotal role in proper MV function: the chords help maintain proper leaflet coaptation and rupture of the chordae tendineae due to disease or aging can lead to mitral valve insufficiency. Therefore, the aim of this study was to characterize the mechanical properties of aged human and ovine mitral chordae tendineae. The human and ovine chordal specimens were categorized by insertion location (i.e., marginal, basal and strut) and leaflet type (i.e., anterior and posterior). The results show that human and ovine chords of differing types vary largely in size but do not have significantly different elastic and failure properties. The excess fibrous tissue layers surrounding the central core of human chords added thickness to the chords but did not contribute to the overall strength of the chords. In general, the thinner marginal chords were stiffer than the thicker basal and strut chords, and the anterior chords were stiffer and weaker than the posterior chords. The human chords of all types were significantly stiffer than the corresponding ovine chords and exhibited much lower failure strains. These findings can be explained by the diminished crimp pattern of collagen fibers of the human mitral chords observed histologically. Moreover, the mechanical testing data was modeled with the nonlinear hyperelastic Ogden strain energy function to facilitate accurate computational modeling of the human MV.
AB - The mitral valve (MV) is a highly complex cardiac valve consisting of an annulus, anterior and posterior leaflets, chordae tendineae (chords) and two papillary muscles. The chordae tendineae mechanics play a pivotal role in proper MV function: the chords help maintain proper leaflet coaptation and rupture of the chordae tendineae due to disease or aging can lead to mitral valve insufficiency. Therefore, the aim of this study was to characterize the mechanical properties of aged human and ovine mitral chordae tendineae. The human and ovine chordal specimens were categorized by insertion location (i.e., marginal, basal and strut) and leaflet type (i.e., anterior and posterior). The results show that human and ovine chords of differing types vary largely in size but do not have significantly different elastic and failure properties. The excess fibrous tissue layers surrounding the central core of human chords added thickness to the chords but did not contribute to the overall strength of the chords. In general, the thinner marginal chords were stiffer than the thicker basal and strut chords, and the anterior chords were stiffer and weaker than the posterior chords. The human chords of all types were significantly stiffer than the corresponding ovine chords and exhibited much lower failure strains. These findings can be explained by the diminished crimp pattern of collagen fibers of the human mitral chords observed histologically. Moreover, the mechanical testing data was modeled with the nonlinear hyperelastic Ogden strain energy function to facilitate accurate computational modeling of the human MV.
KW - Chordae tendineae
KW - Constitutive modeling
KW - Mechanical properties
KW - Mitral valve
KW - Uniaxial test
UR - http://www.scopus.com/inward/record.url?scp=84973922964&partnerID=8YFLogxK
U2 - 10.1016/j.jmbbm.2016.05.034
DO - 10.1016/j.jmbbm.2016.05.034
M3 - Article
C2 - 27315372
AN - SCOPUS:84973922964
VL - 62
SP - 607
EP - 618
JO - Journal of the Mechanical Behavior of Biomedical Materials
JF - Journal of the Mechanical Behavior of Biomedical Materials
SN - 1751-6161
ER -