Infective Endocarditis Flashcards
What is Endocarditis?
- Inflammation of inner layer of heart
What are the two types of endocarditis?
- Endocarditis on normal valves - acute IE
- Endocarditis on abnormal valves - subacute IE
What are the commonest organisms to cause Infective Endocarditis?
- Common in Native valve
- Strep Viridans (50%)
- Staph Aureus (20%)
- IV drug user
- Staph Aureus
- Prosthetic valves
- Staph epidermidis
- enterococcal group
- HACEK group
What does the HACEK gram -ve bacteria represent?
- Haemophilus
- Actinobacillus
- Cardiobacterium
- Eikenella
- Kingella
What are the features of Strep Viridans?
- Optochin resistant
- a-haemolytic
- catalase -
What are the commensals for Strep Viridans?
- Teeth
- Oropharynx
- GI
What is the commonest organism to cause acute infective endocarditis?
- Staph Aureus
How does acute IE present?
- acute heart failure
- emboli
What are the RF for acute IE?
- Dermatitis
- IV lines
- Open wounds
- Renal failure
- DM
What are the RF for subacute IE?
- aortic/mitral disease
- tricuspid valves in IVD users
- prosthetic valves
- congenital heart defects
What 2 presentations will make you think of IE?
- Fever
- New murmur
- Think IE until proven otherwise
What are the Sx for IE?
- Septic signs
- Fever, night sweats, weight loss, anaemia, clubbing
- Cardiac signs
- murmur
- PR prolongation - if aortic root abscess present
- LVF
- Immune complex deposition
- vasculitis
- glomerulonephritis > AKI
- splinter hemorrhage
- janeway lesions
- osler nodes
What ix would you order for IE?
*bolded are key diagnostic ix
- Bedside
- Urine dipstick analysis
- MSU
- ECG
- Bloods
- FBC
- ESR & CRP
- U&E
- LFT
- blood culture
- Imaging
- CXR
- TTE - initial imaging of choice
- TOE
- mitral valve & prosthetic valve vegetations
- aortic root abcess
- septal abcess
- leaflet perforations
How would you diagnose IE?
- Bedside
- Modified Duke criteria
- urinalysis - microscopic haematuria
- ECG - look for HB
- Bloods
- normocytic anaemia
- neutrophilia
- high ESR/CRP
- Rh factor +
- Imaging
- Echocardiogram - vegetations
- Transoesophageal Echocardiogram
- CT - look for emboli
Briefly describe what does the modified Duke criteria for infective endocarditis include?
-
Major criteria
- Positive blood culture
- new valvular regurgitation, (+) echocardiogram
- Endocardial involvement
- Positive echo findings (vegetations, abcess)
- Dehiscence of prosthesis
-
Minor criteria
- Predisposing valve or cardiac abnormality
- Fever >38
- Vascular phenomena
- Embolic phenomenon
- Immunological phenomena
- Positive blood culture not meeting major criteria
- Suggestive echo findings
- Diagnosis = 2 major or 1 major + 3 minor or 5 minor
How would you tx IE?
- Abx
- Surgery
- valve debridement
- valve reconstruction
What type of abx is appropriate if its strep?
- IV benzylpenicillin + low dose gentamicin
- Vancomycin if penicillin allergy
What are the signs of subacute bacterial endocarditis?
- finger clubbing
- roth spots (retinal haemorrhage with pale centre)
- Osler nodes
- Janeway lesions
What type of abx is appropriate if its enterococci?
- IV amoxicillin + low dose Gentamicin
- Vancomycin if pen allergy
What type of abx is appropriate if its staph?
How would you monitor IE’s response to tx?
- Echo - once weekly
- assess vegetation size
- look for valve destruction, intracardiac abcesses
- ECG - twice weekly
- detect conduction disturbancs - sign of aortic root abcess
- Blood test - twice weekly
- ESR, CRP, FBC, U&Es