Cardio 3. Qa 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 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
In community aquired strep veridians is 5-35%, what is it in nosocomial?
Less than 5%, strep veridians seems to be rare in the hospital setting.
How often is nosocomial culture negative
about 5 %, in community aquired it can be up to 30%.
what are some other things that can cause endocarditis?
E.coli, klebsiella and corneybacterium
Why is culture negative increased in community aquired?
Because there is often antibiotic treatment prior to diagnosis.
IF a PCR and full work up is done, what % finds an etiology?
75%.
is there an association between culture negativity and risk factors or etiology
nope
If a culture is negative, what are the most commonly found culperets
Fungi 10%, entercoccus 5%, A-hemolytic strep <5, then the miscelaneous butgs
what can allow bugs into system?
Poor dental health/dental procedures- gentourinary infections, skin infections, IV drugs, pulmonary infections
Clinically, how is endocarditis often classifiec?
acute or subacute
acute endocarditis?
rapidly developing, destructive infection, of an previously normal valve (usually)
what would cause acute endocarditis?
highly virulent organism that can lead to death withing days to weeks in 50% of patients even with vigorous treatment.
Subacute endocarditis
slower less severe course that usually involves and already damaged valve and often a less virulent organism.
what does onset of acute endo look like?
rapidly developing fever, chills, weakness and fatigue with new murmers, and absess development is common
what is the most consistent sign of endocarditis?
fever
why is fever not a reliable finding in subacute endocarditis?
because elderly patients may be unable to generate an appropriate febrile response.
what can be a sign of subacute endocarditis found in a PE?
Petechaiae in mouth, under the tongue and the finger nail beds and in the retina (roths spots)
what are the microemboli under the finger nails called?
splinter hemorrhages
what doe a roth spot look like.
sort of like a flame. Or a rain drop shaped with white or pale centers.
What are roth spots made of?
coagulated fibrin, often caused by immune comples mediated vasculitis resulting from bacterial endocarditis.
In the past, what was the major risk factor for endocarditis?
Rheumtic heart disease
Now that Rheumatic heart disease is more rare, what causes endocarditis.
artificial valves, immunocompromised, IV drug users, alcoholics. Indwelling catheters and those with vascular grafts.
what bacteria is most likely to infect a native valve that has already been damaged?
strep veridans - aka, alpha hemolytic strep.
how often is strep veridens found
its found in 50% of all cases of infectious endocarditis and is the main cause of subacute endocarditis.
Iv drug users are at risk for what bug?
staph aureus
prosthetic valves what bug
staph epidermitis
alcoholics what bugs?
anaerobes and oral cavity bugs
when are gram negative bact like E coli more likely?
after procedrues like cytoscopy or prostatectomy or with indwelling cathaters.
what bacteria is mostl likely seen if you have carcinoma of the colon
Strep bovis - that is why a colonoscopy is indicated whenever you find this bug to rule out colon cancer
why are negative blood cultures so common, 5-20%
antibiotic therapy instituited prior to blood raw, or the organism just not being in the blood at the time of draw. There are also limitations on what the lab can grow.
What is another reason for negative blood cultures?
the endocarditis may be an inflamatory issue rather that caused by a bug.
When can inflammatory vegetations occur
with certain collagen vascular disease like systemic lupus endocarditis.
what can SLE , lupis of the endocarditis also be called
libman-sacks endocarditis**
Flat spreading vegetations may be an indication of what if the person has systemic lupus erythematosus
libman-sacks endocarditis**
What is marantic endocarditis?
Term for endocarditis that results from hypercoaguable state that is known as troussear’s syndrome.
What is trousseau’s syndrome (has a hypercoaguable state) associated with?
Trosseau’s syncrome is a paraneoplastic syndrome that is associated with malignancies
What would a marantic endocardits look like and in who?
with certain collagen vascular disease like systemic lupus endocarditis.
Although merantic vegetations are small, ususally under .5cm why are they still very dangerous.
They are very prone to enbolize
What happens to the valve after the antibiotics sterilize it?
it becomes more fibrotic and scarred, sometimes its damaged enough to cause CHF and then it must be replaced.
Where can the vegetations be found?
they can spread from the valve surface to the endocardial surfice of the myocardium
