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23 Cards in this Set
- Front
- Back
What is the definition of cardiomyopathy? |
heart disease resulting from a primary abnormality in the myocardium |
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What are the three categories of cardiomyopathy and which is the most common?
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Dilated (90%) Hypertrophic Restrictive |
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*What is the ejection fraction in a cardiomyopathy?
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less than 40% (in the presence of increased left ventricular dimension)
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*Which chamber is most affected in cardiomyopathies?
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Left ventricle
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What chambers are affected (and how) in Dilated cardiomyopathy? |
enlargement and dilation of all four chambers |
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What is the most common cause of non-ischemic DCM in the US? |
chronic alcoholism
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What is the second most common cause of non-ischemic cardiomyopathies? (#1 in other parts of the world) |
viral myocarditis |
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What is damaged in DCM and what does it result in?
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-myocytes are injured and necrosis occurs with myocardial fibrosis -when muscle cells fail they dilate |
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Does DCM have a systolic or diastolic dysfunction
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systolic
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What is the number one specific cause of DCM overall?
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ischemic cardiomyopathy (more than 60% of patients with heart failure have this) |
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What is seen histologically in DCM?
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-nonspecific abnormalities-variations in myocyte size -myocyte vacuolization-fibrosis and fat replace myocardium |
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*How does alcoholism lead to DCM?
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-alcohol destroys microvilli brush border and leads to nutritional deficits(thyamine in particular) (glutamine helps regenerate)
-alcohol is toxic to cardiac tissue-> myocyte death |
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What does the heart of someone with DCM resemble?
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basketball
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What is hypertrophic cardiomyopathy caused by? what is it NOT caused by?
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NOT caused by HTN usually genetic predisposition |
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In which chamber are changes seen in HCM?
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L ventricle hypertrophy without ventricular chamber dilation
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What is HCM characterized by?
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-myocardial hypertrophy-abnormal diastolic filling -in 1/3 of cases- intermittent ventricular outflow obstruction |
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Which wall of the ventricle is more hypertrophic in HCM?
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the septum of the L ventricle is larger than the free wall
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What is seen histologically in HCM?
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-hypertrophy of myocardial fibers -interstitial fibrosis |
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Where is the mutation that leads to HCM located?
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any one of several genes that encode proteins within the sarcomere
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What is seen on an Echo for HCM?
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-hypertrophic septum and LV wall -small ejection fraction |
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What happens to the myocardium in restricted cardiomyopathy?
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The myocardium is infiltrated with abnormal tissue-> impaired ventricular wall motion and abnormal contraction and relaxation |
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What are three causes of restrictive cardiomyopathy and which are the most common?
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-amyloidosis- most common
-hemochromatosis-most common iron overload(genetic)- kills cell
-sarcoidosis |
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What population is most susceptible to RCM?
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men of northern European descent |