Bacterial Endocarditis Flashcards
what is bacterial endocarditis?
bacterial infection of endocardium
in which species does bacterial endocarditis impact the mitral or aortic valves most?
dog
cat
horse
swine
what does the proposed pathogenesis of subacute bacterial endocarditis involve?
previously damaged cardiac valve
sterile platelet-rich-fibrin thrombus
bacteremia
high titer of agglutinating antibody against the organism
what can bacteria being shed from the valve lead to?
pyelonephritis and UTI
meningitis
septic arthropathy
myocarditis
what does infection of the valve lead to?
proliferation and fibrous valvular changes
vegetative lesions
what are the four factors that go into subacute bacterial endocarditis?
previously damaged cardiac valve
sterile platelet-fibrin thrombus
bacteremia
high titer of agglutinating antibody against organism
can bacterial endocarditis occur on normal valves?
yes: due to highly pathogenic bacteria
what are the effects of bacterial endocarditis on the mitral valve?
mitral regurgitation
mitral stenosis
left-sided CHF
what can immunologic reaction to chronic infection lead to?
immune-mediated polyarthropathy
glomerulonephritis
positive immunologic tests
what are some historical predisposing factors to bacterial endocarditis?
recent bacteremia
cardiac disease
recent surgery, wounds, IV catheter
immunosuppression
what are some radiographic findings with endocarditis?
cardiac chamber enlargement
evidence of CHF
evidence of pneumonia
pleural effusion
evidence of pulmonary thromboembolism
what is diagnostic accuracy like with echocardiography with endocarditis?
80-90%
what is a common clinical finding with the heart with bacterial endocarditis?
new or changing cardiac murmur
which valve does Bartonella sp impact?
aortic
what are the major criteria for bacterial endocarditis?
positive echocardiographic findings
positive blood cultures in absence of diskospondylitis or obvious sepsis
recent onset diastolic murmur or evidence of more than mild aortic regurgitation
how can you treat bacterial endocarditis?
IV antibiotics 5-14 days
broad spectrum
oral antibiotics 4-8 weeks: culture and sensitivity
no corticosteroids
which type of bacterial endocarditis is more common?
valvular endocarditis
mural less common
what pathogens can adhere to cardiac valves?
Enterococci
Streptococci
Pseudomonas
what pathogens can produce proteases and induce valve injury and facilitate colonization?
Staph
Strep
what are some predisposing factors for bacterial endocarditis?
pre-existing valvular disease
immunosuppressive drugs
recent surgery
recent IV catheter placement
middle-ages, intact male large dogs
antimicrobial use
allergic factor
what are the cardiac effects of bacterial endocarditis of the pulmonic and tricuspid valve?
stenosis or insufficiency of either valve
right CHF
pulmonary thromboembolism
what are the clinical scenarioss of bacterial endocarditis?
congestive heart failure
fever of unknown origin
multisystemic signs suggestive of infection or immune mediated disease
organ embolism
what types of murmurs in dogs and cats are often associated with endocarditis?
diastolic descrendo murmurs
is PT or PTT usually prolonged in bacterial endocarditis?
PTT
what arrhythmias can be seen with endocarditis?
ventricular arrhythmias most common
atrial arrhythmias
AV block
ST segment depression
what is transesophageal echocardiography useful for?
better definition of structures at heart base
improves diagnostic accuracy
what can you culture for bacterial endocarditis?
joint
urine
blood
what are the minor criteria for bacterial endocarditis?
fever
large breed dog
new or worsening systolic murmur
what are some broad spectrum antibiotics used in bacterial endocarditis?
beta-lactams/cephalosporins
with aminoglycoside/fluoroquinolone
what is the overall median survival time of bacterial endocarditis?
72 days
