Infective endocarditis Flashcards
What is infective endocarditis?
Infection of endovascular structures of the heart
What is the strongest RF for developing infective endocarditis?
Previous infection of endocarditis
What are the other possible risk factors for infective endocarditis?
previously normal valves
rheumatic valve disease (30%)
prosthetic valves
congenital heart defects
intravenous drug users (IVDUs
Which valve is most commonly affected in those with previously normal valves?
The mitral valve
Which valve is most commonly affected in IVDU’s?
Tricuspid valve
What is the most common cause of infective endocarditis in the developed world?
Staphylococcus aureus
What is the most common cause of infective endocarditis in the developing world?
Streptococcus viridans
What is the most common cause of infective endocarditis in those who’ve recently had prosthetic valve surgery?
Staphylococcus epidermidis-
commonly colonize indwelling lines
How is infective endocarditis diagnosed?
Via the Modified Duke’s criteria
How is infective endocarditis diagnosed via the modified dukes criteria?
pathological criteria positive, or
2 major criteria, or
1 major and 3 minor criteria, or
5 minor criteria
What is a positive pathological criteria which would confirm infective endocarditis?
Positive histology or microbiology of pathological material
What are the major criteria to confirm a diagnosis of infective endocarditis?
Positive blood cultures
Evidence of endocardial involvement
What blood cultures would confirm infective endocarditis?
Two positive blood cultures showing organisms consistent with IE
persistent bacteraemia from two blood cultures taken > 12 hours apart
What evidence of endocardial involvement would confirms infective endocarditis?
positive echocardiogram
new valvular regurgitation
What are the minor criteria that could indicate infective endocarditis?
predisposing heart condition or intravenous drug use
microbiological evidence does not meet major criteria
fever > 38ºC
vascular phenomena
immunological phenomena
What vascular phenomena is part of the minor criteria for the diagnosis of infective endocarditis?
Major emboli
Splenomegaly
Clubbing
Splinter haemorrhages
Janeway lesions
Petechiae or purpura
What immunological phenomena is part of the minor criteria for the diagnosis of infective endocarditis?
Glomerulonephritis
Osler’s nodes
Roth spots
What are the possible clinical signs of infective endocarditis?
Janeway lesions
Osler nodes
Roth spots
Microscopic haematuria Glomerulonephritis
Splinter haemorrhages
What are Janeway lesions?
Nontender macules on palms and soles
What are Osler nodes?
Tender subcutaneous nodules on the finger pads and toes
What are Roth spots?
Exudative haemorrhagic retinal lesions with pale centres
What are the 2 main signs that would indicate infective endocarditis?
Fever and a new murmur
What is the management of infective endocarditis?
IV antibiotics for 6 weeks (minimum)
What is the management of infective endocarditis of a native valve caused by staphylococci?
Flucloxacillin
If penicillin allergic or MRSA
vancomycin + rifampicin
What is the management of infective endocarditis of the Prosthetic valve caused by staphylococci?
Flucloxacillin + rifampicin + low-dose gentamicin
If penicillin allergic or MRSA
vancomycin + rifampicin + low-dose gentamicin
What is the management of infective endocarditis caused by fully-sensitive streptococci (e.g. viridans)?
Benzylpenicillin
If penicillin allergic
vancomycin + low-dose gentamicin
What is the most likely cause if the patient is an IVDU drug user?
Staph aureus
What is the most common cause if the patient has recently had a dental proceedure or as poor dental hygiene?
Streptococcus viridans
What is the most common cause if the patient has previously undergone prosthetic valve surgery?
Staphylococcus epidermis
