Rheumatic Fever and Endocarditis Flashcards
What is rheumatic fever?
Systemic febrile illness due reaction from Group A beta-haemolytic strep infection, usually within the past 2-6 weeks. 2% of the population are susceptible and may lead to damaged heart valves.
Caused by Streptococcus pyogenes usually
What are the diagnsotic criteria for rheumatic fever?
Major Criteria Carditis: 1 of changes murmur, CCF, cardiomegaly, friction rub and +ve echo Polyarthritis Erythema marginatum Subcutaneous nodules Sydenham’s chorea
Minor Criteria Fever CRP raised Arthralgia but no swelling ECG prolonged PR interval Previous rheumatic fever or heart disease
Need 2 major or 1 major and 2 minors plus evidence of preceding strep infection e.g. strep throat, scarlet fever or +ve throat swabs
Knees, ankles, elbows and wrists are all commonly effected and very painful but there are no long-term effects of this
How is rheumatic fever managed?
Rest and immobilisation Aspirin high dose Prednisolone Phenoxymethylpenicillin for pharyngitis Benzylpenicillin
What are the clinical features of infective endocarditis?
Fever Splenomegaly Clubbing Splinter haemorrhages Anaemia Rash Heart failure Microscopic haematuria New murmur
What diagnostic criteria are used for infective endocarditis?
Infective endocarditis diagnosed if: • pathological criteria positive, or • 2 major criteria, or • 1 major and 3 minor criteria, or • 5 minor criteria
Pathological criteria
Positive histology or microbiology of pathological material obtained at autopsy or cardiac surgery (valve tissue, vegetations, embolic fragments or intracardiac abscess content)
Describe the major and minor criteria used in the modified duke criteria for infective endocarditis?
Major criteria
• Two positive blood cultures showing typical organisms
• Positive serology for Coxiella burnetii, Bartonella species or Chlamydia psittaci, or
• Positive molecular assays for specific gene targets
• Evidence of endocardial involvement Positive echocardiogram, or new valvular regurgitation
Minor criteria
• Predisposing heart condition or intravenous drug use
• Microbiological evidence does not meet major criteria
• Fever > 38ºC
• Vascular phenomena: major emboli, splenomegaly, clubbing, splinter haemorrhages, Janeway lesions, petechiae or purpura
• Immunological phenomena: glomerulonephritis, Osler’s nodes, Roth spots
What organisms usually cause infective endocarditis?
Streptococcus’ and Staphylococcus’
What are poor prognostic factors in infective endocarditis?
Poor prognostic factors – Staph Aureus, prosthetic heart valves, culture negative and low complement levels
How should suspected infective endocarditis be investigated?
Echo
Blood cultures at different times and sites
How is infective endocarditis treated and when is surgery indicated?
Benzylpenicillin and gentamicin
Indications for surgery
• Severe valvular incompetence
• Aortic abscess (often indicated by a lengthening PR interval)
• Infections resistant to antibiotics/fungal infections
• Cardiac failure refractory to standard medical treatment
• Recurrent emboli after antibiotic therapy
