Applying harmonic optical microscopy for spatial alignment of atrial collagen fibers

• Published in: PloS one 2010-11, Vol.5 (11), p.e13917-e13917
• Main Authors: Chiu, Yu-Wei, Lo, Men Tzung, Tsai, Ming-Rung, Chang, Yi-Chung, Hsu, Rong-Bin, Yu, Hsu-Yu, Sun, Chi-Kuang, Ho, Yi-Lwun
• Format: Article
• Language: English
• Subjects: Aged; Algorithms; Alignment; Atrial fibrillation; Atrial Fibrillation - blood; Atrial Fibrillation - metabolism; Atrial Fibrillation - pathology; Biomarkers - blood; Cardiac arrhythmia; Cardiology; Cardiovascular disease; Cardiovascular Disorders/Arrhythmias, Electrophysiology, and Pacing; Cell Biology/Extra-Cellular Matrix; Collagen; Collagen Type I - blood; Collagen Type I - chemistry; Collagen Type I - metabolism; Electrical engineering; Energy; Energy distribution; Entropy; Extracellular matrix; Female; Fibers; Fibrillation; Fibrosis; Fourier transforms; Harmonics; Heart; Heart Atria - metabolism; Heart Atria - pathology; Heart diseases; Heart failure; Heart surgery; Humans; Imaging, Three-Dimensional - methods; Internal medicine; Interstitial collagenase; Male; Matrix metalloproteinase; Matrix Metalloproteinase 1 - blood; Medicine; Metalloproteinase; Microscopy; Microscopy - instrumentation; Microscopy - methods; Microscopy, Confocal - instrumentation; Microscopy, Confocal - methods; Middle Aged; Optical fibers; Optical microscopy; Optics; Pathology/Cellular Pathology; Patients; Peptide Fragments - blood; Procollagen - blood; Rhythm; Scanners; Signal transduction; Sinus; Spatial distribution; Spectra; Surgery; Tissue inhibitor of metalloproteinase 1; Tissue Inhibitor of Metalloproteinase-1 - blood; Tissues; Transformation
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0013917

Atrial fibrosis creates a vulnerable tissue for atrial fibrillation (AF), but the spatial disarray of collagen fibers underlying atrial fibrosis is not fully elucidated. This study hypothesizes that harmonics optical microscopy can illuminate the spatial mal-alignment of collagen fibers in AF via a layer-by-layer approach. Atrial tissues taken from patients who underwent open-heart surgery were examined by harmonics optical microscopy. Using the two-dimensional Fourier transformation method, a spectral-energy description of image texture was constituted and its entropy was used to quantify the mal-alignment of collagen fibers. The amount of collagen fiber was derived from its area ratio to total atrial tissue in each image. Serum C-terminal pro-collagen pro-peptide (CICP), pro-matrix metalloproteinase-1 (pro-MMP-1), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) were also evaluated. 46 patients were evaluated, including 20 with normal sinus rhythm and 26 with AF. The entropy of spectral-energy distribution of collagen alignment was significantly higher in AF than that in sinus rhythm (3.97 ± 0.33 vs. 2.80 ± 0.18, p