Cardio III - Q2,1 Flashcards
What is cardiomyopathy?
Disease of the heart where the cause is intrinsic to the myocardium itself, such as inflmmatory disorders, autoimmune, and metabolic diseases
What is cardiomyopathy used to describe
heart disease resulting from a primary abnormality in the myocardium
What are the 3 major categories of cardiomypathy?
Dilated - 90%, hypertrophic and restrictive
How would dilated cardiomyopathy be described
Ejection fraction of less than 40% in the presence of increased left ventricular demension (end size >115%)
how is dialated cardiomyopathy different from hypertrophic and restrictive.
dilated- the heart is bigger and the chambers are bigger, Hypertrophic-the heart may be bigger, but the Left ventricle or chamber is smaller. Restrictive- the walls just aren?t flexable like they should be.
In dialated cardiomyopathy, what chambers are dilated?
all 4 champers are enlarged and dilated.
What is the cause of dialated cardiomyopathy?
Idiopathic dialated cardiomyopathy.
What is the most common cause of non-ischemic dialated cardiomyopahty in the us?
chronic alcholism
What does DCM dialated cardiomyopathy look like
nonspecific abnormalities, monocyte size variation, vacuolation , loss of myofibrillar material and fibrosis.
why would a heart have a globoid shape
because all the chambers are dilated
What is HCM, hypertrophic cardiomyopathy characterized by?
characterized by myocardial hypertrophy, abnormal diastolic filling,
wht is present in about 1/3 of HCM cases in addition to the myocardial hypertrophy and abnormal diastolic filling
intermittent ventricular outflow obstruction
what does HCM look like microscopically
Hypertrophy of myocardial fibers that have a prominent dark nuclei along with interstitial fibrosis
what is the cause of HCM
Inherited- autosomal dominant trate. It?s a problem of some genes that code for sarcomeres.
compare the contracttion of DCM to HCM
HCM is thick walled and hypercontracting while DCM is flabby and hypo-contracting
essential feature of HCM?
massive myocardial hypertrophy without ventricular dilation
which parts of HCM are hypertrophic?
Its ususally only the one ventricle
classic appearance of HCM grossly is what?
disproportinate thickening of the ventricular septum as compred with the free wall of the ventricle.
what are the 2 most common causes of restrictive cardiomyopathy
amyloidosis and hemochromatosis
what happens in restrictive cardiomyopathy
the myocardium is infiltrated with abnormal tissue that impairs wall motion and abnormal contratcion/relaxation
What stain can show hemochromatosis?
prussian blue.
what does excessive depositon of iron in heart lead to?
Heart enlargement and failure. It?s a form of restrictive cardiomyopathy
what does amylodosis look like on slide in heart?
amorphus deposits of pale point material between myocardial fibers.
what does endocarditis refer to?
Inflammation on the valve leaflets. Endocardial lining of heart may also be involved
where does endocarditis ususally begin
lines of closure where the pressure is greatest
What organism causes the majority of community aquired endocarditis?
Staph aureus, but not the MRSA type.
After staph aureus, what causes Community aquired endo?
Strep veridans, 10-35, enterococcus 5-10%, culture neg 5-10%, Fungi <5%,
Infectious endocarditis vegetations are what?
bulky masses on valves colonized by bacteria and thrombic debris.
what valves are most commonly infected ?
Left sided valves, probably because there is more pressure on that side, Its also about equal between mitrial and aortic valves
what is friable vegitation?
how portions of vegetation breaks off and can embolize throughout the body.
what does infectious endocarditis lead to?
destruction of underlying valves and tissue, and the vegetations can embolize and carry infectious agents anywhere.
endocarditis generally refers to what?
bacterial endocarditis because generally its bacterial in nature.
how often can the culter of the endocarditis turn up negative?
5-30% of the time.
What organism is the most common nosocomial cause of endo?
Staph Aureus, 60-80%, and unlike community aquired its mostly MRSA