Infective Endocarditis Flashcards
Characteristics of endocarditis
- Fever
- Persistent bacteremia
- Vegetation on endothelial surface of heart
Characteristics of endocardial vegetation
- Variable size
- Mass made of fibrin and platelets
- Lots of microbes
- Few inflammatory cells
What are the 4 types of IE?
- Native valve IE
- Prosthetic valve IE
- IV drug abuse IE
- Nosocomial IE
What classifies acute IE?
- Affects normal heart valves
- Rapidly destructive
- Metastatic foci
- Most commonly caused by Staph
- W/O Tx is fatal within 6 weeks
What classifies subacute IE?
- Often affects damaged heart valves
- Slower progression
- W/O Tx is fatal in 1 year
What are the risk factors for IE?
- IVDU
- Artificial heart valves and pacemakers
- Acquired heart defects
- Congenital heart disease
- Intravascular catheters
In general, what are the top 3 major causes of IE?
- S. aureus
- Viridans group (Strep)
- CNS
What is the most common cause of culture negative IE?
Prior antibiotic therapy
Outline the patho of IE
- Turbulent blood flow makes the endocardial surface sticky
- Bacteremia brings microbes to the sticky surface
- These organisms adhere to the endocardial surface
- Over time they invade the heart valve leaflets
List the destructive local effects of IE
- Valve distortion/destruction
- Chordal rupture
- Perforation
- Paravalvular abscess
- Conduction abnormalities
- Purulent pericarditis
- Valve obstruction
Clinical features of IE
- Fever
- Splenomegaly
- Heart murmurs
- Peripheral signs
- Emboli
What are the peripheral signs of IE?
- Splinter hemorrhage
- Oslers nodes
- Janeway lesions
- Subconjunctival hemorrhage
What are Janeway lesions?
- Erythematous, blanching macules
- Non-painful
- Located on palms and soles
Where do you find Roth’s spots?
In the eye
What investigations are appropriate for suspected IE?
- Blood cultures
- CBC
- CRP
- Urinalysis
- Renal and hepatic profile
- ECG
- TTE or TEE
Lab abnormalities associated with IE
- Anemia
- Leukocytosis
- Thrombocytopenia
- Urinalysis abnormalities
- Elevated liver enzymes
- Abnormal CSF
Which has higher sensitivity, TTE or TEE?
TEE (75-95% vs < 60%)
What are the indications for TEE?
- Definite or suspected IE
- Persistent bacteremia (5-7 days) with antibiotic Tx
- Persistent emboli
- Conduction deficits
- Pre and peri-operative assessment
- S. aureus bacteremia
How many blood cultures should be drawn for suspected IE?
Somebody please edit, not clear from lecture…
What are the 3 categories under the Modified Duke Criteria?
- Definite
- Possible
- Rejected
What are the pathological criteria for definite IE?
Microorganisms - culture/histology in a vegetation/emboli/intracardiac abscess OR
Pathologic lesions - vegetations or intracardiac abscess present, confirmed by histology
What are the clinical criteria for definite IE?
2 major criteria OR
1 major and 3 minor criteria, OR
5 minor criteria
What are the clinical criteria for possible IE?
1 major and 1 minor criteria OR
3 minor criteria
How might you reject the Dx of IE?
- Confirmed alternative Dx, OR
- Resolution with antibiotics for 4 days or less, OR
- No pathological evidence of IE in surgery/autopsy, after antibiotics for 4 days or less
What are the major criteria for IE?
- Positive blood cultures
2. Evidence of endocardial involvement
What defines a +ve blood culture for IE?
- Typical microorganism found from 2 separate blood cultures
- Persistently +ve culture
- Single +ve culture for coxiella or IgG Ab titre > 1:800
What constitutes evidence of endocardial involvement for IE?
On echo..
- Oscillating intracardiac mass
- Abscess
- New partial dehiscence of a prosthetic valve
OR - new valve regurgitation
What are the minor criteria for IE?
- Predisposing heart condition or IVDU
- Fever (38)
- Vascular phenomena (Janeway lesions, splinter hemorrhage)
- Immunologic phenomena (glomerulonephritis, Osler’s nodes, Roth spots, etc.)
What is the empiric Tx for IE in IVDU?
Vancomycin or Daptomycin
What is the empiric Tx for native valve IE?
- Penicillin G or Ampicillin + Cloxacillin + Gentamicin, OR
2. Vancomycin + Gentimycin
What is the empiric Tx for prosthetic valve IE?
- Vancomycin + Gentamicin + Rifampicin
IE is associated with a high mortality, T or F?
True
What is endocarditis?
An infection of the endocardial surface of the heart
