Infective endocarditis Flashcards
1
Q
Definition of infective endocarditis
A
- Infection of the endocardial surface of the heart
- Classification based on etiologic agen
- Pathogenesis: hematogenous spread via bacteremia, and subsequent adherence to (usually) damaged valves
- Vegetations allow bacterial growth within a protective sheath of fibrin, platelets, and RBCs
2
Q
Common infectious causes of endocarditis (GP cocci)
A
- Staph aureus: most common bacterial cause, results in rapid mortality w/o antibio Rx
- Usually more virulent, can affect normal valves and comes from hospitals or IV drugs
- Viridians strep: alpha-hemolytic, live in oral cavity
- Usually infect only damaged valves, more sub-acute Sx
3
Q
Other infectious causes of endocarditis
A
- Group D strep (S gallolyticus bovis): associated w/ colon CA, all pts should get colonoscopy
- Nutritionally deficient strep (abiotrophia, granulicatella)
- HACEK: GN coccobacilli of normal oral flora
- H= haemophilus
- A= actinobacillus
- C= Cardiobacterium
- E= Eikenella
- K= Kingella
- Culture negative: fungi, rickettsiae, chlamydia
4
Q
Prosthetic valve IE
A
-Coagulase negative staph (S epidermitidis) most common
5
Q
Physical findings in IE
A
- Fever, MSK Sx
- Changing murmur
- Peripheral stigmata: splinter hemorrhages (linear under nails), petechiae, osler nodes (tender nodules on digits), janeway lesions (painless macules on palms and soles), roth spots (retinal hemorrhage w/ clear center)
6
Q
Complications of IE
A
- CHF
- Peripheral emboli (brain, kidney)
- Glomerulonephritis
- Stroke
- (!)Mycotic aneurysm (often in brain): due to bacterial invasion, emboli, or immune complex deposition
7
Q
Criteria for Dx (duke)
A
- Major: 2 separate positive blood cultures
- Evidence of endocardial involvement (vegetations) on echo
- Need 2 major, or 1 major 3 minor or 5 minor
- Minor: IVDU, any of the peripheral stigmata, etc
8
Q
Rx of IE
A
- Bacteristatic antibios will not work, must use bactericidal
- Indications for surgery: refractory CHF, >1 serious embolic episode, uncontrolled bacteremia >7days, inter cardiac abscess, persistent fever >7 days, fungal endocarditis