Infective endocarditis Flashcards
Define infective endocarditis
An infection of the innermost layer of the heart, usually the valves
How many of the Dukes criteria are required for a diagnosis of infective endocarditis?
2 major criteria OR 1 major and 3 minor criteria OR 5 minor criteria
What are the 3 major criteria?
- Persistent bacteraemia (>2 +ve blood cultures)
- Vegetations/new regurge seen on echo
- +ve serology for bartonella, coxiella or brucella
What are the 6 minor criteria?
- Predisposing risk factors eg murmur, IVDU
- Fever >38C or high CRP
- Evidence of immune complex formation: splinter haemorrhages, haematuria
- Vascular phenomena: major arterial emboli - stroke, PE
- Positive echo findings but not meeting major criteria
- Positive blood culture that does not meet major criteria
How does infective endocarditis often present (in a non-acute presentation)?
Symptoms v non-specific: - Fever (usually PUO) Anorexia Weight loss Malaise Fatigue Rigors Night sweats Weakness
What are 3 acute symptoms of infective endocarditis?
SOB
Chest tightness
Embolic complications
List 8 important factors to look for in PMH/SHx of a pt with suspected infective endocarditis
Recent dental work Rheumatic fever Congenital heart disease Valve replacement Long term lines Previous bacteraemias (S. aureus, enterococcus) GI/bowel issues IVDU
What might be heard on auscultation of a pt with infective endocarditis?
New and changing heart murmurs
List 7 subacute signs that may be detected on examination of a pt with infective endocarditis
Clubbing Splinter haemorrhages Osler's nodes Janeway lesions Roth spots (retinal hemorrhages with pale centers) Splenomegaly Haematuria
A mnemonic for the main signs and symptoms of infective endocarditis is FROM JANE, what does this stand for?
Fever Roth's spots Osler's nodes Murmur Janeway lesions Anemia Nail hemorrhage Emboli
Which investigations are appropriate when diagnosing infective endocarditis?
Urinalysis FBC (↓Hb) U&E CRP (to monitor therapy) ESR 3x blood cultures w/o Abx Serology (if cultures -ve) CXR Echo
Which pathogen is likely to be responsible for subacute bacterial endocarditis (SBE)?
Low virulence strep (often Strep viridians)
How does subacute bacterial endocarditis compare to more acute forms of infective endocarditis?
Mild-moderate illness progressing over weeks-months
↓propensity to haematogenously seed extracardiac sites
Describe the onset of acute bacterial endocarditis
Fulminant disease emerges in days - weeks
Which pathogen is most likely to be responsible for acute bacterial endocarditis?
Staph. aureus (frequently “metastatic” infection from elsewhere in body.
Which type of staph is most likely to be responsible for prosthetic valve endocarditis?
Coagulase negative staphylococci
What is the most common cause of -ve cultures in infective endocarditis?
Cultures taken after antibiotic therapy started
Other than strep and staph, which other pathogens can cause infective endocarditis?
- Aspergillus
- Brucella
- Coxiella
- Chlamydia
- Mycoplasma
- The HACEK of fastidious gram -ves (Haemophilus parainfluenzae, Aggregatibacter/Actinobacillus, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae)
What is the empirical treatment for acute infective endocarditis of a native valve?
Flucloxacillin
What is the empirical treatment for indolent infective endocarditis of a native valve?
Penicillin AND gentamicin
What is the empirical treatment for infective endocarditis of a prosthetic valve?
Vancomycin AND gentamicin
What is the treatment for confirmed Strep viridans endocarditis?
Benzylpenicillin AND gentamicin
What is the treatment for confirmed MSSA endocarditis?
Flucloxacillin for 4 weeks
What is the treatment for confirmed MRSA endocarditis?
Vancomycin AND Gentamicin/Rifampicin/Rucidin
What is the treatment for confirmed enterococcal endocarditis?
Ampicillin AND gentamicin
Which valves are most commonly involved in infective endocarditis?
Aortic and mitral
Which valve is affected in 50% of IVDUs aged 20-24?
Tricuspid
What comorbidity makes an IVDU more susceptible to infective endocarditis?
HIV +ve
Which organism most commonly causes infective endocarditis in IVDUs?
S. aureus/polymicrobial
List 7 indications for surgical intervention in infective endocarditis
>1 serious systemic embolus / high risk Uncontrolled infection Significant valve dysfunction Lack of response to antibiotics Local supurative complication eg perivalvular abscess Congestive heart failure Prosthetic valve endocarditis
