Open AccessQuantitative Analysis of Fiber Disarray Developing in Papillary Muscles Unloaded after Mitral Valve Replacement
Author(s) -
Tezuka Fumiaki,
Sato Ikuro,
Mori Hiroki,
Nomura Masuko,
Hort Waldemar
Publication year - 1989
Publication title -
acta patholigica japonica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 74
ISSN - 0001-6632
DOI - 10.1111/j.1440-1827.1989.tb02430.x
Subject(s) - papillary muscle , fiber , anatomy , muscle fibre , chemistry , medicine , organic chemistry , skeletal muscle
Muscle fiber disarray which developed in the papillary muscle released from its chordal attachment after mitral valve replacement (MVR) was analysed histometrically in 23 hearts. The degree of disarray, or how far the fiber arrangement deviated from an ideal condition in which the fibers are considered to be aligned in parallel, was evaluated in terms of the “disarray index”. This index corresponds to the ratio of the minor to major axes of a regression ellipse which can be obtained histometrically by plotting the reciprocal of the number of muscle fibers intersected by a test line of equal length in every direction on a polar coordinate system. The index can vary continuously in a range from 0.00 for a completely parallel fiber alignment to 1.00 for a completely random distribution. The estimated index showed a gradual increase from 0.05 to 0.68 according to the postoperative survival period after MVR with a significant positive correlation (r=0.793, p< 0.01). The index was inversely correlated with the mean muscle fiber diameter (r=‐0.433, p<0.05). These results indicate that the disarray which develops in the papillary muscle after MVR is a deformation of the normally parallel arrangement of fibers toward an isotropic texture under focal disruption of the normally longitudinally oriented tensile force. Acta Pathol Jpn 39: 779‐785, 1989.