Obesity reduces left ventricular strains, torsion and synchrony in mouse models: a cine DENSE MRI study
© Kramer et al; licensee BioMed Central Ltd. 2013
Published: 30 January 2013
Obesity is an epidemic affecting over 1 in 3 adults in the United States. Patients who are obese have increased cardiovascular mortality compared to those with normal weight, partly due to direct effects on the heart. However, the effect of obesity on advanced measures of cardiac function such as strain, torsion and synchrony are poorly understood.
Left ventricular sub-epicardial strain was significantly lower in the obese mice with a 40% reduction in circumferential strain (p<0.001), a 19% reduction in longitudinal strain (p=0.03), and a 53% reduction in radial strain (p=0.06). By contrast, left ventricular sub-endocardial strain was modestly reduced in the obese mice in the circumferential direction by 12% (p=0.01), and not significantly different in the radial (p=0.63) or longitudinal (p=0.44) directions. Peak left ventricular torsion was reduced by 34% in the obese mice (p=0.06). Finally, the radial uniformity of strain index showed a reduction in the synchrony of contraction in the left ventricle (p=0.01) with a time delay in the septal to free wall direction.
Diet-induced obesity leads to a reduction in cardiac contractility in mouse models as evidenced by reductions in left ventricular strains and torsion. Reductions in cardiac strain are mostly limited to the sub-epicardial layer of the left ventricle, with relative preservation of function in the sub-endocardium. Diet-induced obesity also leads to reduced synchrony of contraction in the left ventricle of the heart.
Change due to high-fat diet
Radial Strain (%)
Circumferential Strain (%)
Longitudinal Strain (%)
Radial Uniformity of Strain
Peak Torsion (°/mm)
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