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Your search keyword '"Cardiomyocyte architecture"' showing total 3 results
Start Over Descriptor "Cardiomyocyte architecture" Topic diffusion tensor magnetic resonance imaging
3 results on '"Cardiomyocyte architecture"'

2. Region-Specific Microstructure in the Neonatal Ventricles of a Porcine Model

Author

Raj Prabhu, Michael David Jones, Shwe Soe, Peter Theobald, Ilyas M. Khan, Faizan Ahmad, Richard Johnston, Ian Maconochie, Nick White, and Jun Liao

Subjects
0301 basic medicine, Technology, Swine, Fibre dispersion, Fibre orientation, 030204 cardiovascular system & hematology, 09 Engineering, chemistry.chemical_compound, Engineering, 0302 clinical medicine, ANIMAL-MODEL, Medicine, Myocytes, Cardiac, Neonatal heart structure, Evans Blue, medicine.diagnostic_test, 11 Medical And Health Sciences, Anatomy, Diffusion Tensor Imaging, medicine.anatomical_structure, HEART, Collagen, Diffusion tensor magnetic resonance imaging, LAMELLAR BONE, Second-harmonic generation, Heart Ventricles, CIRCULATION, Biomedical Engineering, Article, 03 medical and health sciences, Region specific, Fractional anisotropy, Animals, Engineering, Biomedical, FETAL, PIG, Fetus, Science & Technology, Two-photon excitation, business.industry, Magnetic resonance imaging, Oxygenation, Apex (geometry), 030104 developmental biology, Animals, Newborn, chemistry, Cardiomyocyte architecture, Ventricle, MECHANICS, CELLS, Anisotropy, business
Abstract

The neonate transitions from placenta-derived oxygen, to supply from the pulmonary system, moments after birth. This requires a series of structural developments to divert more blood through the right heart and onto the lungs, with the tissue quickly remodelling to the changing ventricular workload. In some cases, however, the heart structure does not fully develop causing poor circulation and inefficient oxygenation, which is associated with an increase in mortality and morbidity. This study focuses on developing an enhanced knowledge of the 1-day old heart, quantifying the region-specific microstructural parameters of the tissue. This will enable more accurate mathematical and computational simulations of the young heart. Hearts were dissected from 12, 1-day-old deceased Yorkshire piglets (mass: 2.1–2.4 kg, length: 0.38–0.51 m), acquired from a breeding farm. Evans blue dye was used to label the heart equator and to demarcate the left and right ventricle free walls. Two hearts were used for three-dimensional diffusion-tensor magnetic resonance imaging, to quantify the fractional anisotropy (FA). The remaining hearts were used for two-photon excited fluorescence and second-harmonic generation microscopy, to quantify the cardiomyocyte and collagen fibril structures within the anterior and posterior aspects of the right and left ventricles. FA varied significantly across both ventricles, with the greatest in the equatorial region, followed by the base and apex. The FA in each right ventricular region was statistically greater than that in the left. Cardiomyocyte and collagen fibre rotation was greatest in the anterior wall of both ventricles, with less dispersion when compared to the posterior walls. In defining these key parameters, this study provides a valuable insight into the 1-day-old heart that will provide a valuable platform for further investigation the normal and abnormal heart using mathematical and computational models. Electronic supplementary material The online version of this article (10.1007/s10439-018-2089-4) contains supplementary material, which is available to authorized users.

Published
2018

3. Cardiomyocyte architectural plasticity in fetal, neonatal, and adult pig hearts delineated with diffusion tensor MRI.

Author

Lei Zhang, Allen, John, Lingzhi Hu, Caruthers, Shelton D., Wickline, Samuel A., and Junjie Chen

Abstract

Cardiomyocyte organization is a critical determinant of coordinated cardiac contractile function. Because of the acute opening of the pulmonary circulation, the relative workload of the left ventricle (LV) and right ventricle (RV) changes substantially immediately after birth. We hypothesized that three-dimensional cardiomyocyte architecture might be required to adapt rapidly to accommodate programmed perinatal changes of cardiac function. Isolated fixed hearts from pig fetuses or pigs at midgestation, preborn, postnatal day 1 (P1), postnatal day 5, postnatal day 14 (P14), and adulthood (n = 5 for each group) were acquired for diffusion-weighted magnetic resonance imaging. Cardiomyocyte architecture was visualized by three-dimensional fiber tracking and was quantitatively evaluated by the measured helix angle (αh). Upon the completion of MRI, hearts were sectioned and stained with hematoxylin/eosin (H&E) to evaluate cardiomyocyte alignment, with picrosirius red to evaluate collagen content, and with anti-Ki67 to evaluate postnatal cell proliferation. The helical architecture of cardiomyocyte was observed as early as the midgestational period. Postnatal changes of cardiomyocyte architecture were observed from P1 to P14, which primary occurred in the septum and RV free wall (RVFW). In the septum, the volume ratio of LV- vs. RV-associated cardiomyocytes rapidly changed from RV-LV balanced pattern at birth to LV dominant pattern by P14. In the RVFW, subendocardial αh decreased by ∼30∘ from P1 to P14. These findings indicate that the helical architecture of cardiomyocyte is developed as early as the midgestation period. Substantial and rapid adaptive changes in cardiac microarchitecture suggested considerable developmental plasticity of cardiomyocyte form and function in the postnatal period in response to altered cardiac mechanical function. [ABSTRACT FROM AUTHOR]

Published
2013
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