cardiovascular system
small heart
(
J:258831
)
• hearts become smaller with age
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• the heart weight-to-body weight ratio is lower in 5-6 month old mice and in 11-12 month old males
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• 5-6 month old mice exhibit mild fibrosis in hearts while 11-12 month old mice show severe fibrotic lesions in hearts
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• stroke work is reduced in 11-12 month old females
• end-diastolic pressure, and end-diastolic PV relation (EDPVR) are higher in 11-12 month old mice, indicating diastolic dysfunction
• systolic indices of cardiac output, stroke volume, end-systolic volume, and end-diastolic volume are reduced in older males
• ESPVR (slope of the end-systolic PV relation) in males and PRSW (pre-load recruited SW-slope of the SW-EDV relationship) is females are lower, indicating impaired systolic function in older mice
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• 5-6 and 11-12 month old males exhibit reduced cardiac output
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• 5-6 month old males exhibit a decrease in stroke volume
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• females show an increase in the relaxation time, Tau at 5-6 and 11-12 months of age while males show an increase at 11-12 months of age
• 5-6 month old mice show a trend in lower peak rate of left ventricular relaxation (-dP/dtmin) suggesting diastolic dysfunction
• mitral valve Doppler assessment shows an increase in the isovolumetric relaxation time in 11-12 month old males
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• echocardiography indicates decreased left ventricular inner diameter in diastole and systole in 5-6 and 11-12 month old males and decreased interventricular septum in sytole in 11-12 month old males
• however, systolic function is preserved, with no differences in ejection fraction and fractional shortening in young or old mice
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• papillary muscle fibers from 6 month old males and 11-12 month old males and females show increased maximal force indicating hypercontractility
• papillary muscle fibers from males show a small increase in the calcium-sensitivity of force
• small angle X-ray diffraction shows reduced interfilament lattice spacing measured under relaxation conditions in papillary muscle fibers and the level of passive tension in response to muscle stretch is increased indicating increased muscle stiffness
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• left ventricle inner diameters in diastole and systole are smaller in young and old males indicating a more pronounced restrictive cardiomyopathy in males than females
• hearts do not show hypertrophic growth
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homeostasis/metabolism
• 11 month old mice show an increase in hydroxyproline content in the heart
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muscle
• females show an increase in the relaxation time, Tau at 5-6 and 11-12 months of age while males show an increase at 11-12 months of age
• 5-6 month old mice show a trend in lower peak rate of left ventricular relaxation (-dP/dtmin) suggesting diastolic dysfunction
• mitral valve Doppler assessment shows an increase in the isovolumetric relaxation time in 11-12 month old males
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• left ventricle inner diameters in diastole and systole are smaller in young and old males indicating a more pronounced restrictive cardiomyopathy in males than females
• hearts do not show hypertrophic growth
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• myocardium shows sarcomere irregularities with Z-lines streaming and M-lines vanishing in 11 month old mice
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• M-lines vanish in 11 month old myocardial fibers
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• 11 month old myocardial fibers show Z-lines streaming
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Mouse Models of Human Disease |
DO ID | OMIM ID(s) | Ref(s) | |
restrictive cardiomyopathy | DOID:397 |
OMIM:115210 OMIM:PS115210 |
J:258831 |