Cardiology: 8.5: Endocarditis Flashcards
What is endocarditis?
inflammation of the endocardium, esp. that which lines the surface of the cardiac valves
What is nonbacterial thrombotic endocarditis?
sterile valve vegetations
What is the hemolysis pattern of Strep. viridans?
alpha
Strep. viridans can only infect which heart valves?
previously damaged valves
Dx?
- sterile valve vegetations from SLE
- Libman-Sacks endocarditis
- “LSE in SLE”
What lab findings are seen in endocarditis?
- positive blood cultures
- anemia of chronic disease (low MCV, low hemoglobin)
- high ferritin = TIPC low = serum Fe decreased
What valves does Staph. aureus infect?
normal valves, esp the tricuspid
What is the gram stain and morphology of Staph. epidermidis?
gram positive cocci in clusters
Is Strep. viridans catalase positive or negative?
negative
What is the hemolysis pattern of Strep. bovis?
gamma (no hemolysis)
What kind of endocarditis do the HACEK organisms cause? Why?
- endocarditis w/ negative blood cultures
- they’re hard to grow
What detects lesions on heart valves?
trans-esophageal echo (TEE)
What is the endocarditis called when caused by Staph. aureus?
acute endocarditis
You discover that your pt has endocarditis from Strep. bovis. What do you do next?
check for colorectal carcinoma
What are Janeway lesions?
- erythematous, nontender lesions on the palms and soles
- assoc with endocarditis
Why can Strep. viridans attach to damaged heart valves?
- the thrombotic vegetations that form trap these bacteria
- bc the bugs make dextrans
What are the HACEK organisms?
- Hemophilus
- Actinobacillus
- Cardiobacterium
- Eikenella
- Kingella
What are painful lesions on the fingers and toes assoc. with endocarditis called?
Osler nodes
Where does nonbacterial thrombotic endocarditis arise? What does this cause?
- on the mitral valve along the lines of closure
- regurg
What is Libman-Sacks endocarditis?
- sterile valve vegetations from SLE
- “LSE in SLE”
What heart findings are associated with SLE?
- Libman-Sacks endocarditis:
- vegetations on the surface and undersurface (both sides) of the mitral valve
- mitral regurg
- *** “LSE in SLE”
Which bug commonly infects prosthetic heart valves?
Staph. epidermidis
What is the endocarditis caused by Strep. viridans called?
subacute endocarditis
What is the most common cause of endocarditis in IV drug abusers?
Staph. aureus
Where is Strep. viridans a normal flora of the body?
in the mouth/oropharynx
Dx?
- vegetations on the surface and undersurface (both sides) of the mitral valve with mitral regurg
Libman-Sacks endocarditis
Name a common way Strep. viridians enters the bloodstream.
dental work
What is the gram stain and morphology of Strep. bovis?
gram positive cocci in chains
How can Strep. bovis be differentiated from Group D strep/enterococci?
does not grow in 6.5% NaCl
Is Viridans strep optochin sensitive or resisitant?
sensitive
What are the s/s of endocarditis?
- fever
- murmur (bc of vegetations on the valves) –> :
- Janeway lesions (erythematous, nontender lesions on the palms and soles)
- Osler nodes (painful lesions on the fingers and toes)
- splinter hemorrhages in the nailbeds
- anemia of chronic disease
What do thrombotic vegetations consist of? What do they attach to?
- platelets + fibrin
- subendothelial collagen and tissue factor
Where does Libman-Sacks endocarditis occur? What does this cause?
- on the surface and undersurface (both sides) of the mitral valve
- mitral regurg
Dx?
- vegetations on the mitral valve along the lines of closure with mitral regurg
nonbacterial thrombotic endocarditis
Is Staph. epidermidis catalase positive or negative?
positive
What is the morphology of Strep. viridans?
gram positive cocci in chains
What does Staph. aureus do to heart valves?
large vegetations destroy the valve –> acute endocarditis
Is Staph. epidermidis novobiocin sensitive or resistant?
sensitive
What are Osler nodes?
painful lesions on the fingers and toes assoc. with endocarditis “Ouch Ouch Osler”
What happens in endocarditis caused by Strep. viridans?
small vegetations form which do not destroy the valve
What is a consequence of valve vegetations?
they can embolize (septic embolization)
What is the most common overall causative organism of endocarditis?
Strep. viridans
What causes nonbacterial thrombotic endocarditis?
- a hypercoagulable state
- underlying adenocarcinoma
Which bug commonly infects pts with underlying colorectal carcinoma?
Strep. bovis
Is Staph. epidermidis coag positive or negative?
negative
What usually causes endocarditis?
bacterial infection
How can Strep. viridans be distinguished from S. pneumo?
Viridans is not encapsulated
What are erythematous, nontender lesions on the palms and soles assoc. with endocarditis called?
Janeway lesions
