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| ==Causes== | | ==Causes== |
| *'''1- Impaired extent and/or speed of myocardial relaxation:'''
| | [[Diabetes]] |
| **Myocardial relaxation is an ATP dependent process regulated by the rate of re-uptake of cytoplasmic calcium into the sarcoplasmic reticulum.
| | [[Diastolic dysfunction]] |
| **Low concentration of calcium, as seen in [[ischemia]], is associated with a slowed down myocardial relaxation.
| | Hypertrophy of the heart(for example, as seen in [[hypertension]]) |
| *'''2- Increased myocardial stiffness:'''
| | Ischemia |
| **Myocardial stiffness can be secondary to cardiac muscle hypertrophy (for example as seen in [[hypertension]]). Concentric hypertrophy (increased mass and relative wall thickness) and remodelling (normal mass but increased wall thickness) are associated with diastolic dysfunction due to impaired filling.
| | [[Infiltrative diseases]] ( for example, [[amyloidosis]]) |
| **Myocardial stiffness can be the result of [[infiltrative diseases]] like [[amyloidosis]].
| | [[Mitral stenosis]] |
| **Scarred heart muscle, occurring after a heart attack, are relatively stiff.
| | Pricardial compression |
| **[[Diabetes]] can be a cause of cardiac stiffness as a result of [[glycosylation]] of the heart muscle.
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| *'''3- Extrinsic constraints:'''
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| **Extrinsic constraints can be seen in pericardial compression.
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| *'''4- Chamber dilatation:'''
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| **Severe systolic dysfunction that has led to ventricular dilation can be associated with diastolic dysfunction. When the ventricle has been stretched to a certain point, any further attempt to stretch it more, as by blood trying to enter it from the left atrium, meets with increased resistance and thus decreased compliance.
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| *5'''- Miscelleneous:'''
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| **In [[mitral stenosis]], blood cannot readily flow out from the [[left atrium]] into the [[left ventricle]] since the valve between those two heart chambers is blocked which causes the blood to back up into the left atrium and, eventually, the lungs. [[Pulmonary edema]] may result.
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| **Diastolic dysunction secondary to [[mitral stenosis]] is especially seen when the heart rate is elevated, as occurs in [[exercise]] and [[pregnancy]]. Thus, there will be insufficient time for the blood to traverse the narrowed passageway (i.e. [[mitral valve]]) between the [[left atrium]] and [[left ventricle]].<ref>Mann D.L., Chakinala M. (2012). Chapter 234. Heart Failure and Cor Pulmonale. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.</ref>
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| ==References== | | ==References== |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Assistant Editor(s)-in-Chief: Rim Halaby
Overview
Diastolic dysfunction is the mechanical abnormality of the heart to properly relax and fill with blood during diastole. Several medical conditions may lead to diastolic dysfunction and they include impaired myocardial relaxation, increased myocardial stiffness and extrinsic constraint on the heart.
Causes
Diabetes
Diastolic dysfunction
Hypertrophy of the heart(for example, as seen in hypertension)
Ischemia
Infiltrative diseases ( for example, amyloidosis)
Mitral stenosis
Pricardial compression
References
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