Regional variations in ex-vivo diffusion tensor anisotropy are associated with cardiomyocyte remodeling in rats after left ventricular pressure overload.

Autor: Carruth ED; Department of Bioengineering, University of California San Diego, La Jolla, California, USA., Teh I; Leeds Institute of Cardiovascular & Metabolic Medicine, University of Leeds, Leeds, UK., Schneider JE; Leeds Institute of Cardiovascular & Metabolic Medicine, University of Leeds, Leeds, UK., McCulloch AD; Department of Bioengineering, University of California San Diego, La Jolla, California, USA., Omens JH; Department of Bioengineering, University of California San Diego, La Jolla, California, USA. jomens@ucsd.edu.; Department of Medicine, University of California San Diego, La Jolla, California, USA. jomens@ucsd.edu., Frank LR; Department of Radiology, University of California San Diego, La Jolla, California, USA.
Jazyk: angličtina
Zdroj: Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance [J Cardiovasc Magn Reson] 2020 Apr 02; Vol. 22 (1), pp. 21. Date of Electronic Publication: 2020 Apr 02.
DOI: 10.1186/s12968-020-00615-1
Abstrakt: Background: Pressure overload left ventricular (LV) hypertrophy is characterized by increased cardiomyocyte width and ventricle wall thickness, however the regional variation of this remodeling is unclear. Cardiovascular magnetic resonance (CMR) diffusion tensor imaging (DTI) may provide a non-invasive, comprehensive, and geometrically accurate method to detect regional differences in structural remodeling in hypertrophy. We hypothesized that DTI parameters, such as fractional and planar anisotropy, would reflect myocyte remodeling due to pressure overload in a regionally-dependent manner.
Methods: We investigated the regional distributions of myocyte remodeling in rats with or without transverse aortic constriction (TAC) via direct measurement of myocyte dimensions with confocal imaging of thick tissue sections, and correlated myocyte cross-sectional area and other geometric features with parameters of diffusivity from ex-vivo DTI in the same regions of the same hearts.
Results: We observed regional differences in several parameters from DTI between TAC hearts and SHAM controls. Consistent with previous studies, helix angles from DTI correlated strongly with those measured directly from histological sections (p < 0.001, R 2  = 0.71). There was a transmural gradient in myocyte cross-sectional area in SHAM hearts that was diminished in the TAC group. We also found several regions of significantly altered DTI parameters in TAC LV compared to SHAM, especially in myocyte sheet angle dispersion and planar anisotropy. Among others, these parameters correlated significantly with directly measured myocyte aspect ratios.
Conclusions: These results show that structural remodeling in pressure overload LV hypertrophy is regionally heterogeneous, especially transmurally, with a greater degree of remodeling in the sub-endocardium compared to the sub-epicardium. Additionally, several parameters derived from DTI correlated significantly with measurements of myocyte geometry from direct measurement in histological sections. We suggest that DTI may provide a non-invasive, comprehensive method to detect regional structural myocyte LV remodeling during disease.
Databáze: MEDLINE
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