Microbial infection of endocardial surface, usually a heart valve.
Causes
- • Staph aureus (acute)
- • Viridans streptococci (subacute)
- • Enterococcus
- • HACEK
- • Candida (prosthetic, IVDU)
Risk factors
- • Prosthetic valve
- • IVDU
- • Congenital / rheumatic heart disease
- • Indwelling lines
- • Recent dental work
Clinical features
- • Fever, malaise, weight loss
- • Night sweats, arthralgia
- • New / changing murmur
- • Embolic phenomena
Examination
- • Splinter haemorrhages, Osler nodes, Janeway lesions
- • Roth spots, conjunctival petechiae
- • Splenomegaly
Investigations
- • 3 sets of blood cultures from separate sites ≥1 h apart BEFORE antibiotics
- • TTE then TOE if suspicion remains
- • FBC, CRP, ESR, U&E, urinalysis
- • ECG (PR prolongation → aortic root abscess)
Diagnosis
- • Modified Duke criteria: 2 major OR 1 major + 3 minor OR 5 minor
Differential diagnosis
- • Rheumatic fever
- • SLE / Libman-Sacks
- • Atrial myxoma
- • Marantic endocarditis
Management
- • Empirical: vancomycin + gentamicin (native) or vancomycin + gentamicin + rifampicin (prosthetic) until cultures back
- • 4–6 weeks targeted IV antibiotics
- • Surgery if heart failure, abscess, persistent bacteraemia, large vegetation >10 mm with emboli
Drug therapy
- • Flucloxacillin 2 g IV q4h (MSSA)
- • Vancomycin 15–20 mg/kg q12h (MRSA)
- • Benzylpenicillin 2.4 g IV q4h (strep)
- • Gentamicin 1 mg/kg q8h
Complications
- • Heart failure
- • Septic emboli (stroke, splenic, renal)
- • Mycotic aneurysm
- • AV block
Prevention
- • Prophylaxis only for high-risk patients undergoing high-risk dental procedures (AHA)
Follow-up
- • Repeat TTE end of therapy
- • Inflammatory markers weekly
- • Dental review
Clinical pearls
- • Negative cultures: think Coxiella, Bartonella, Brucella, HACEK, fungi
- • Tricuspid IE in IVDU → septic pulmonary emboli on CXR
References
- • ESC Endocarditis 2023
- • AHA 2015 IE Guideline
Related in WardRound
Educational — verify locally.
