Endocarditis Flashcards
Explain the steps from a mechanical endocardial injury to baterial endocarditis
mechanical damage - release of tissue factor, thromboplastin, extracellular matrix proteins –> clot formation
fibrinogen binds to bacteria
fibronectin causes endothelial cell internalization of bacteria
How do bacteria causing endocarditis escape the immune system?
internalization
What immune-mediated diseases are associated with endocarditis and how do they develop?
Polyarthritis
glomerulonephritis
endocarditis causes antibody complexes and complement complex depositions
What location of endocarditis is more likely to cause thromboembolism?
mitral
Thromboembolic disease from endocarditis most commonly leads to infarction in what organs?
kidneys and spleen
What is the most common presenting complaint of endocarditis?
lameness
What structural heart disease predisposes to infectious endocarditis?
subaortic stenosis
List common causes of bacteriemia that have shown to cause endocarditis
UTIs
indwelling urinary catheters
dyskospondylitis
pneumonia
pyoderma
periodontal disease
What is the recommendation for prophylactic Abx therapy for dental procedures?
only if aortic stenosis or other congenital heart disease present
What are the most common bacterial causes for endocarditis
Staph
Strep
E.Coli
more now: Bartonella
What valve is usually affected by Bartonella endocarditis?
aortic
What type of murmur and pulse pressure changes may be noted with aortic endocarditis?
diastolic murmur form aortic insufficiency
increased pulse pressure –> bounding pulses
List the 4 types of arrhythmias reported with endocarditis in order of frequency. Which valve affected is more likely to cause arrhythmias?
Ventricular tachyarrhythmias
SVTs
AV block
Afib
Aortic more prone
Overall common in IE —> 40-70%
What changes are typically seen on a coagulation profile in a dog with endocarditis?
increased FDP and D-dimer
hyperfibrinogenemia
thrombocytopenia
What is the pathognomonic echo lesion for endocarditis?
vegetative oscillating lesion
How should you adjust your blood culture sampling if the patient is already on Abx?
get culture samples at time of trough
What are the 4 Major criteria of the Modified Duke Criteria?
- vegetative lesion/erosive lesion/abscess
- positive blood culture (2 or more positive, or 3 or more of common skin contaminants)
- new valvular insufficiency
- more than mild aortic insufficiency in abscence of subaortic stenosis
What are the 7 Minor criteria of the Modified Duke Criteria?
- fever
- subaortic stenosis
- blood culture not meeting major criteria
- Bartonella serology > 1:1024
- IMPA or glomerulonephritis
- thromboembolic disease
- large dog > 15kg
What defines a Definitve Diagnosis for the Modified Duke Criteria?
- histopath
- 2 major
- one major + 2 minor
What defines a Possible Diagnosis for the Modified Duke Criteria?
- 1 major + 1 minor
- three minor
What defines a Unlikely Diagnosis for the Modified Duke Criteria?
- resolution in less than 4 days
- other diagnosis was made
- no evidence at necropsy
What is the recommended empiric Abx therapy until the culture is back, or if the culture is negative and bacterial infection is suspected?
Amikacin + ampicillin/sulbactam if kidney function okay
What is the recommended treatment length for IV and oral antimicrobial therapy in endocarditis?
1-2 weeks IV, 6-8 week oral
When rechecking a patient with infectious endocarditis after 1 week of Abx therapy, the vegetative lesions has not improved. How do you adjust the Abx theray?
broaden spectrum
What is the current recommendation for antithrombotic therapy in endocarditis?
not recommended
What are risk factors for early cardiovascular death?
- thromboembolic disease
- azotemia
- CHF
