Cardiovascular - Endocarditis + Myocarditis Flashcards
Primary infectious endocarditis
primary infectious heart disease
microorganisms invade valvular endothelium and cause proliferative or erosive lesions
2 valves commonly affected by animals with infective endocarditis?
mitral and aortic
vegetative lesions
platelets, fibrin, microorganisms and inflammatory cells - she bacteria internalized by endothelium (walled off) and are not well accessible to immune system or treatments
Structural changes to the valve from the infection typically lead to severe valvular _______ that often develops acutely.
regurgitation
T/F: the clinical signs associated with infective endocarditis are localized to the heart
false, causes systemic disease so can see fever, anorexia and lethargy
Which of the following is FALSE regarding infective endocarditis?
A) can be caused by pyoderma
B) likelihood of getting it is increased if an animal has sub aortic stenosis
C) most common presenting complaint is lameness
D) is not accompanied with a heart murmur
D - most dogs do present with a heart murmur
Clinical syndromes associated with infective endocarditis
Immune mediated disease - mass antibody formation leads to immunocomplexes + deposition in organs, poly arthritis and glomerulonephritis most common
CHF + arrhythmias - valve damage = mitral/aortic regurgitation, CHF develops in 75% cases
Thromboembolic disease - kidneys, spleen, myocardium, brain, lungs
Signalment of animals with infective endocarditis
middle aged to older dogs, male, medium to large breeds
German shepherds, golden retriever, Labrador retriever
Clinical signs of infective endocarditis
Most common presenting sign - lameness
also - lethargy, hyporexia, tachypnea, cough, dyspnea, weakness, fever
may have recent history of infection
You are conducting a follow up appointment on a dog that recently had a pyometra. You notice that the dog is showing signs of lameness. You auscultate and hear a systolic murmur. Considering the history and clinical presentation, what is your likely diagnosis?
mitral valve infective endocarditis
Which bacteria that causes infective endocarditis does not cause a fever and why?
Bartonella - hides from immune system so won’t see fever
T/F: animals with infective endocarditis rarely present with a fever
False, they commonly do
murmur heard with mitral infective endocarditis?
left apical systolic
murmur heard with aortic infective endocarditis?
left basilar diastolic
T/F: arrhythmias are common with infective endocarditis
true
what arrhythmias are seen with infective endocarditis
ventricular and/or supra ventricular premature beats or tachycardia, 3rd degree AV block
Common CBC abnormalities of infective endocarditis
leukocytosis, neutrophilia, monocytosis, thrombocytopenia, mild anemia
biochemical abnormalities of infective endocarditis
hypoalbuminemia, azotemia, elevated liver enzymes, proteinuria, hematuria, pyuria, hemoglobinuria, bacteria
Aside from albumin, what other protein may be lost in urine due to glomerular disease?
antithrombin 3
- this aids in clot breakdown so patient will be prothrombotic
T/F: urine culture should be performed in IE patients
True
When should you obtain a diagnostic blood test for infective endocarditis?
A) 3 days after antibiotic treatment
B) Blood tests are not used to diagnose infective endocarditis
C) Prior to antithrombotic therapy
D) none of the above
C - should be taken prior to antibiotic therapy
Which is FALSE regarding blood cultures to diagnose infective endocarditis?
A) 3-4 samples should be collected and submitted for aerobic and anaerobic culture
B) different venous sites should be used
C) it is an aseptic procedure
D) all samples should be taken at the same time
D - they should be taken 30mins to 1h apart
Diagnostic testing options for infective endocarditis
blood cultures, thoracic rads, echocardiogram, ECG if arrhythmia auscultated
T/F: vegetative lesions are visible on an echocardiogram
True - appear as a blob on the valve
Mainstay of therapy for infective endocarditis A) Fluid therapy B) euthanasia C) long term bactericidal D) diuretics
C - usually a betalactam +/- amino glycoside or enrofloxacin
If CHF present in infective endocarditis, should you treat it?
yes
Prognosis of infective endocarditis
valve damage often permanent even after infection is resolved
dogs with aortic IE usually have grave prognosis
How can you prevent infective endocarditis?
dogs with congenital heart disease (especially sub aortic stenosis) should receive periprocedural antibiotics (B-lactam, cephalosporin)
Define myocarditis
myocardial inflammation in the absence of schema resulting in myocyte damage and cardiac dysfunction
Most common cause of myocarditis
infectious causes
T/F: there is a very specific clinical presentation of myocarditis
false, non-specific
Clinical signs of myocarditis
fever, lethargy, hyporexia, resp signs, syncope, muscle pain, diarrhea
PE findings seen in myocarditis
arrhythmia, murmur,, abnormal lung sounds, fever, lymphadenopathy
What is commonly seen on a myocarditis ECG?
ventricular premature complexes
What biomarker test is useful to hep confirm diagnosis of myocarditis?
cardiac troponin I - leaked from damaged/necrotic cardiomyoctes into circulation
Treatment of myocarditis
anti-arrhythmic drugs and supportive care
treat underlying cause
Important cause of myocarditis in Texas and Southern USA
Chagas Disease, trypanosome cruzi
Acute - lethargy, generalized lymphadenopathy, paleo, hepatosplenomegaly, sudden death
Chronic - progressive R sided cardiac dysfunction and CHF
Dx - serology, trapomastigotes on blood smear
Tx - clinical signs
