Infective Endocarditis And Rheumatic Heart Disease Flashcards
What is IE?
Inflammation of inner heart
Usually involves the valves
Vegetations: platelets, fibrin, microorganisms
What are IE predisposing conditions?
Prosthetic valves
Cardiac devices
IV drug use
Congenital heart disease
RHD
valve prolapse
Immunosuppression
Clinical signs of IE?
Oiler nodes
Splinter haemorrhage
PR prolongation, av block
Roth spots
Jane way lesions
IE symptoms?
Fever (90%)
-chills/rigors
-poor appetite
-weight loss
Heart murmur (85%)
Emboli phenomena (25%)
How to diagnose IE?
Laboratory
-elevated crp
-erythrocyte sedimentation
-leucocytoses
-anaemia
-microscopic haematuria
Blood cultures 3 times 30 minutes apart (essential to do this before antibiotic therapy)
What imaging should be used in suspected IE?
Trans thoracic echocardiography (important)
CT/MRI for emboli
PET maybe
Major Duke’s Criteria (IE)?
Typical microorganisms consistent with IE (S viridans, S bovis, HACEK organisms, S aureus without other primary site, enterococcus), from two separate blood cultures
Microorganisms consistent with IE from persistently positive blood cultures (>= 2 blood cultures drawn > 12 hours apart, all of three blood cultures, or majority of four or more blood cultures)
Single positive blood culture for Coxiella burnetti or positive antibody titre
Echocardiogram positive for IE e.g. vegetation, abscess, partial dehiscence of prosthetic valve, new valvular regurgitation
Abnormal activity around site of prosthetic valve implantation on PET-CT
Paravalvular lesions on cardiac CT
Minor Duke’s criteria (IE)?
Predisposition e.g. predisposing heart condition or intravenous drug use
Fever > 38.0°C
Vascular phenomena e.g. arterial emboli, infarcts, mycotic aneurysms, intracranial or conjunctival haemorrhages, Janeway lesions
Immunological phenomena e.g. glomerulonephritis, Osler’s nodes, Roth’s spots, rheumatoid factor
Microbiological evidence e.g. blood culture not meeting major criteria, or serological evidence of active infection with organism consistent with IE
What is required of the Duke’s criteria to be sure of IE?
two major criteria, one major + three minor criteria, or all five minor criteria
IE treatment?
long term IV antibiotics 6 weeks minimum). initially broad spectrum but can be rationalised to more specific ones when the organism and it’s sensitivities are known.
For prosthetic valves add rifampicin and gentamicin
When is surgery indicated in IE?
Heart failure with valvular dysfunction or cardiac complications
Uncontrolled infection
Persistent fever and positive blood cultures
Prevention of embolism
If the vegetation is persistently large (>10mm).
One or more embolic episodes
Where is RHD common?
Developing world
What pathogen causes rheumatic fever?
Group A beta-haemolytic strep
(strep pharyngitis)
Natural history of RHD?
Group A beta-haemolytic strep infection (5-15 yo)
Acute rheumatic fever (carditis, painful joints
Years later: Rheumatic heart disease: progressive valvular disease after years of rheumatic fever (clinical or subclinical)
Clinical features of RHD?
Clinical features
Dyspnoea
Symptoms of heart failure
Non specific ecg changes, may show enlarged left atrium or ventricle
