Pathology: Infection of the endocardium usuallylining the heart valves.
Vegetationscomprising of fibrin, platelets and micro-organisms degrade valves.
Aortic valve most commonly affected followed by mitralthen tricuspid valves
Fever + new murmur = endocarditis until provenotherwise.
Aetiology: Normal heart valves: StreptococcusViridans
Risk factors for normal valves: diabetes,renal failure, immunosuppression
Abnormal valves: Staphylococcus Aureus from skin
Risk factors for abnormal valves: Valvedisease, prosthetic valve, IV drug use
(Tricuspidvalve most often affected), Cyanotic congenital heart failure
Other organisms: Staphylococcus epidermis, Enterococcus Faecalis,
HACEKorganisms (Haemophilus, Actinobacillus, actinomycetemcomitans, Cardiobacteriumhominis, Eikenella, Kingella), Mycobacteria, Chlamydia, Coxiella
Symptoms: Fever, rigors, night sweats, malaise,anorexia, anaemia, weight loss, stroke.
Signs: Clubbing,new murmur, splenomegaly, petechiae, Osler’s nodes (painful finger pulpnodules), Janeway lesions (painless palmar lesion), splinter haemorrhages, RothSpots (retinal haemorrhages), microscopic haematuria, glomerulonephritis.
Investigations: Bloods: FBC, U&E, LFT, Clotting, CRP
Blood Cultures: 3 sets at differenttimes from different sites
Urine: microscopic haematuria
ECG: Prolonged PR interval or AV nodeblock
ECHO: Assess for vegetations, abscess,congenital lesions and LV function
Diagnosis: Based on ModifiedDukes Criteria
Definite – 2 major criteria,1 major and 3 minor criteria or 5 minor
criteria
Possible – 1 major and 1 minorcriteria or 3 minor criteria
Treatment: Streptococcus Viridans: 4weeks IV benzylpenicillin and gentamicin followed
by 2 weeks of oral penicillin
Staphylococcus Aureus: Flucloxacillin and gentamicin (MSSA) or Vancomycin
and gentamicin (MRSA) in addition rifampicinis
required for prosthetic valves for MSSA orMRSA.
Surgical: Prosthetic valvedehiscence, fungal infections, poor antibiotic response
severe heart failure and aortic root abscess withheart block
Complications: Septic emboli, acute heart failure,valve regurgitation, septic shock
Prognosis: 30% mortality with Staphylococcal infections. 6% mortalitywith Streptococcus.
