Obesity reduces left ventricular strains, torsion, and synchrony in mouse models: a cine displacement encoding with stimulated echoes (DENSE) cardiovascular magnetic resonance study

Journal of Cardiovascular Magnetic Resonance

Research

Lisa A Cassis¹  Frederick H Epstein²  David K Powell³  Andrea C Mattingly³  Christopher M Haggerty³  Sage P Kramer³  Cassi M Binkley³  Brandon K Fornwalt⁴ 

[1] Department of Molecular and Biomedical Pharmacology, University of Kentucky, Lexington, KY, USA;Departments of Biomedical Engineering and Radiology, University of Virginia, Charlottesville, VA, USA;Departments of Pediatrics, Physiology and Medicine, University of Kentucky, 800 Rose St, MN-150, 40536, Lexington, KY, USA;Departments of Pediatrics, Physiology and Medicine, University of Kentucky, 800 Rose St, MN-150, 40536, Lexington, KY, USA;Graduate Center for Biomedical Engineering, University of Kentucky, Lexington, KY, USA;

关键词: Obesity;    Mouse;    Cardiovascular magnetic resonance;    DENSE;    Strain;    Heart;   

DOI  :  10.1186/1532-429X-15-109

 received in 2013-03-07, accepted in 2013-12-11,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundObesity affects a third of adults in the US and results in an increased risk of cardiovascular mortality. While the mechanisms underlying this increased risk are not well understood, animal models of obesity have shown direct effects on the heart such as steatosis and fibrosis, which may affect cardiac function. However, the effect of obesity on cardiac function in animal models is not well-defined. We hypothesized that diet-induced obesity in mice reduces strain, torsion, and synchrony in the left ventricle (LV).MethodsTen 12-week-old C57BL/6 J mice were randomized to a high-fat or low-fat diet. After 5 months on the diet, mice were imaged with a 7 T ClinScan using a cine DENSE protocol. Three short-axis and two long-axis slices were acquired for quantification of strains, torsion and synchrony in the left ventricle.ResultsLeft ventricular mass was increased by 15% (p = 0.032) with no change in volumes or ejection fraction. Subepicardial strain was lower in the obese mice with a 40% reduction in circumferential strain (p = 0.008) a 53% reduction in radial strain (p = 0.032) and a trend towards a 19% reduction in longitudinal strain (p = 0.056). By contrast, subendocardial strain was modestly reduced in the obese mice in the circumferential direction by 12% (p = 0.028), and no different in the radial (p = 0.690) or longitudinal (p = 0.602) directions. Peak torsion was reduced by 34% (p = 0.028). Synchrony of contraction was also reduced (p = 0.032) with a time delay in the septal-to-lateral direction.ConclusionsDiet-induced obesity reduces left ventricular strains and torsion in mice. Reductions in cardiac strain are mostly limited to the subepicardium, with relative preservation of function in the subendocardium. Diet-induced obesity also leads to reduced synchrony of contraction and hypertrophy in mouse models.

【 授权许可】

Unknown   
© Kramer et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.