<3 anatomy
this is the layer of the heart that becomes inflamed during IE
endocardium
this organism is classically associated with acute IE
s. auereus
This group of gram-positive, alpha-hemolytic, catalase-negative cocci normally lives in the oropharynx and is associated with subacute IE
viridans group streptococci
This glycopeptide antibiotic binds D-Ala-D-Ala and inhibits bacterial cell-wall synthesis.
vancomycin
these tender, red-purple nodules on the fingers are caused by immune-complex deposition
osler nodes
this valve separates the left atrium from left ventricle
mitral valve
this organism is classically associated with subacute IE involving a previously damaged valve
viridans group streptococci
This finding distinguishes viridans streptococci from S. pneumoniae (viridans is resistant to this test)
optochin
Flushing and itching of the neck and torso during a rapid vancomycin infusion is known as this reaction
red man syndrome
these brown streaks underneath the nails result from microemboli damaging capillaries
splinter hemorrhages
these structures attach the mitral valve leaflets to papillary muscles and prevent prolapse during systole
chordae tendineae
days of high fever, rigors, and rapid valve destruction suggests this type of IE
acute IE
a patient develops prosthetic valve IE three weeks after surgery. this organism group is the likely culprit
coagulase-negative staphlyocci
This third-generation cephalosporin inhibits peptidoglycan cross-linking by binding PBPs and can be used for viridans streptococcal IE
ceftriaxone
explain why IE leads to an elevated rheumatoid factor
persistent bacteremia causes chronic antigenic stimulation, polyclonal B-cell activation, and immune-complex formation, producing a positive RF
explain how vegetation can lead to murumurs
thickened leaflet with vegetation -> irregular surface -> incomplete seal when closed -> blood is forced thorugh @ higher turbulence -> MURMUR
subacute IE
this event can cause transient bacteremia that allows viridans streptococci to seed a damaged heart valve.
dental procedures
Blood cultures reveal fully penicillin-susceptible viridans streptococci. what treatment change would you make?
vancomycin -> ceftriaxone
true/false: positive blood cultures > 2 times 12 hrs apart are sufficient to diagnose IE
false!
duke's major criteria: blood culture + echocardiographic evidence of endocardial involvement
a patient has severe mitral regurgitation from ruptured chordae. name a chamber that would experience volume overload
left atrium/left ventricle
Explain why S. aureus can infect a previously normal valve while viridans streptococci generally require a damaged valve.
S. aureus is highly virulent and can directly invade an intact valve, whereas viridans streptococci are lower-virulence organisms that typically require pre-existing endothelial injury/NBTE as a site for bacterial adherence.
Put this pathway in the correct order: rheumatic heart disease → untreated GAS pharyngitis → molecular mimicry → chronic valve damage.
Untreated Group A Strep pharyngitis → molecular mimicry/autoimmune response → acute rheumatic fever → valvulitis → chronic rheumatic heart disease → damaged valve susceptible to IE.
This type of healthcare facility can provide low-cost or sliding-scale care and is an important resource for refugees and immigrants who may lack insurance.
Federally Qualified Health Center (FQHC)
A patient with a damaged valve has a vegetation. Explain the entire sequence from endothelial injury to formation of an infected vegetation.
Turbulent/high-velocity flow → endothelial injury → platelet/fibrin deposition → NBTE → transient bacteremia → bacterial adherence to the platelet-fibrin nidus → bacterial proliferation protected within the fibrin mesh → vegetation formation