Lecture 22: Fever and a New murmur Flashcards
Clinical features of endocarditis?
Symptoms of infection: fever, lethargy, gradual?
Embolic phenomena: Splinter haemorrhages, sometimes conjunctival
Valve abnormal: Early diastolic murmur (aortic regurgitation)
Mitral stenosis
Aortic stenosis
Aortic regurg
Mitral stenosis: A soft, long diastolic murmur
Aortic stenosis: High pitched cresendo-decresecendo systolic murmur
Aortic regurg; A soft, early diastolic murmur
Endocarditis pathogenesis?
- turbulent flow through abnormal valve
- Platelets and fibrin attach to damaged valvular epithelium forming sterile vegetation’s
- Transient bacteriemia seeds onto sterile vegetations
- Infected vegetations enlarges and sheds infected emboli and leads to valvular destruction
Endocarditis microbial aetiology
MOSTLY viridans streptococci, which are alpha haemolytic. Resident in mouth, gut etc
Then staph aureus, then enterococcus faecalis, HACEK
Continuous bacteraemia and endocarditis
With typical infections, times of transient bacteraemia
Bacteria always shed, so all blood cultures positive with an organism.
Culture blood on 3 occasions at least 20 mins apart, 90/100% +ve (so next few hours, or days) with an organism that can cause endocarditis
Treatment for endocarditis
Bactericidal antibiotic for weeks Dependent on organisms IV, high dose, 2-4 weeks. 70-90% cure rate Strep viridans: penicillin + gentamicin Staph: flucloxacillin Enterococcus: amoxycillin + gentamicin
Rheumatic fever versus endocarditits
Strep pyogenes pharyngitis ONLY, immune response to GAS leading to inflammation of joints, valves, heart, skin, brain. INFLAMMATION, not infection. Immunologic damage to valves. Oral penicillin 10 days, prophylaxis IM penicillin for many years. May however be a damaged heart valve eg in childhood
Endocarditis: Viridans step + others, mouth commensals, valve INFECTION, vegetation, treat IV penicillin for one month, prophylaxis with oral penicillin when dental work