L4: infective endocarditis Flashcards
colonization of heart valves with microbial organisms causing friable infected vegetations and valve injury:
infective endocarditis
what kind of vegetations are created in infective endocarditis ?
large vegetations that may affect any valve in the heart
which type of lesions are the most common in infective endocarditis ?
left sided lesions of the aortic and mitral valves
what are the differenced between acute and subacute infective endocarditis ?
- valves affected
-type of vegetations
-organism
-fatality
-nature
acute :
-affects normal heart valves : producing necrotizing , ulcerative invasive infection
-produced bulky vegetations)
-if not treated , fatal in 6 months
-rapidly destructive
-commonly caused by staphylococcus aureus
-metastatic foci
-embolic complications
-quick onset
subacute:
-affects damaged heart valves
-if not treated , fatal by 1 year . less fatal than acute
-indolent nature (doesn’t expand)
-slow onset
-caused by streptococci viridians(associated with low virulance)
-produces smaller vegetations
risk factors for infective endocarditis :
-dental procedures that cause bleeding
- oral and URT surgery
-genitourinary surgery
-intravenous drug use
- prosthetic heart valves
-congenital heart defects
-catheters in right heart
-intravascular catheters
what are some common organisms that cause bacterial endocarditis ?
staphylococcus aureus / streptococcus
enterococci
infective endo carditis is a system disease not just a cardiovascular one
:D
manifestations of infective endocarditis may be the result of :
-direct effects of organism
-embolism
-immunological responses
symptoms of acute and subacute infective endocarditis :
acute :
-high grade fever
-arthralgias/myalgias
-abdominal pain
-pleuritic chest pain
-back pain
subacute :
-low grade fever
-anorexia
-fatigue
-arthralgias/myalgias
-abdominal pain
signs of infective endocarditis:( non specific)
-fever
-heart murmur
-non-specific signs :
petechiae
subungual “splinter” hemorrhages
clubbing
splenomegaly
neurologic changes
SPECIFIC signs :
oslers nodes , janeway lesions , and roth spots
essential blood tests for infective endocarditis :
blood cultures (minimum of 3 at 3 different venipuncture sites)
-typical organism presents in at least 2 separate samples
-atypical persistently positive blood cultures :
- 2 positive cultures obtained 12 hours apart
- three or more positive cultures in which the first and last samples were collected at least 1 hour apart
why may false negative blood cultures occur when testing for infective endocarditis ?
prior antibiotic therapy
special organisms : chlamydia , fungi , viruses
non-infective endocarditis: sterile thrombotic endocarditis
first line indication if infective endocarditis is suspected :
transthoracic echocardiography (native valves)
ma 5as but :
transesophageal echocardiography :
-prosthetic valves
-fungal or S. aureus or bacterium
how is infective endocarditis diagnosed ?
according to dukes criteria :
2 major or 1 major and 3 minor or all 5 minor criteria
