Endocarditis Flashcards
infective endocarditis
infection of the heart valves and/or endocardium
INFLAMMATORY process (unlike degenerative valve diseases)
causes multisystemic disease w/ severe CV consequences
pathogenesis of endocarditis
- area of endothelial injury to valve - onset of endocarditis requires a pre-existing lesion to the endothelium of the valve (ex. SAS)
- portal of entry - bacteria enters through oral, GI, urinary, skin, respiratory, etc infections
- bacterial adherence - blood flow through the heart causes bacteria to adhere to the lesions on the valve surface FACING blood flow
- platelet and fibrin deposition allows bacterial adherence and colonization forming a vegetative lesion
gross lesion of endocarditis
vegetative lesions
- bacteria, inflammatory cells, platelets, thrombin, fibrin
- roughened
- white to yellow
- cauliflower like
- hemorrhagic
what valves are most commonly affected
mitral (atrial side)
aortic (ventricular side)
what bacteria are most commonly associated with endocarditis in dogs
streptococcus
staphylococcus
E. coli
bartonella
what bacteria are most commonly associated with endocarditis in cats
pasteurella
what CV consequences occur with endocarditis
- valve regurgitation
- septic emboli
- fever
- cardiac arrhythmias
- mural infection or infarction
- AV block
- cardiomegaly (DCM phenotype)
does valve regurgitation resolve once the endocarditis is treated
no - causes permanent remodeling
multisystemic consequences of endocarditis
- septic shock
- fever
- thromboembolic injury to other tissues
- acute kidney injury
- immune mediated disease due to immune complex deposition
clinical signs of endocarditis
- historical or current infection
- immunosuppression (drugs or disease related)
- fever
- polyarthritis - shifting leg lameness
- lethargic/ill
- NEW heart murmur
- tachycardia, arrhythmias, hyperkinetic pulses, CHF
what is the MOST important test for endocarditis
blood cultures
always get 3 samples from 3 different sites
can still get a negative culture with endocarditis (bartonella)
what can be identified on echo
thick, irregular valve
independently oscillating
valve regurgitation
predisposing factors (ex. SAS)
what are the 3 major criteria for diagnosing endocarditis
- echo - vegetative, oscillating lesion
- new heart murmur
- positive blood culture in >2 samples
treatment for endocarditis
- antibiotics > 8 weeks
- clavamox, baytril, doxycycline - antiplatelet - clopidogrel
endocarditis prognosis
guarded to poor
negative prognostic indicators:
- azotemia
- CHF
- thromboembolic complications
