Name a bacteria that can infect prosthetic materials such as replacement heart valves, but is also a common skin contaminant.
What is important when taking blood cultures (for endocarditis)?
Take 3 sets - evidence of continuing bacteraemia/rule out contamination
Take before giving antibiotics
If negative, consider serology for unusual organisms
Give some risk factors for endocarditis.
Heart valve abnormality
Prosthetic heart valve
IV drug use
What is the pathogenesis of endocarditis?
Turbulent blood flow over a damaged heart valve causes the deposition of platelets and fibrin upon which bacteria can form a vegetation
What is the danger with infected vegetations on heart valves?
Infected vegetations are friable and can break off, lodging in capillary beds causing abcesses or (fatal) haemorrhage
Which valves are most commonly affected by endocarditis?
Mitral and aortic valves
How does endocarditis usually present?
overwhelming sepsis and cardiac failure
What are subacute presentations of endocarditis?
Give some signs of a subacute presentation of endocarditis.
New/changing heart murmur
Roth spots, Janeway lesions, Osler nodes
After blood cultures, what is the standard investigation for endocarditis?
What is the difference in causative organisms for early (within 60 days) and late presentations of prosthetic valve endocarditis?
Early - usually Staph. epidermidis or Staph. aureus
Late - co-incidental bacteraemia, wide range of possible organisms
What are the typical features of endocarditis in IV drug users?
Right-sided endocarditis - tricuspid valve
Usually Staph. aureus, may present as 'pneumonia'
May not require valve replacement, but long term prognosis poor
What are the empirical treatments for endocarditis?
High-dose, frequent IV antibiotics.
Native valve - Benzylpenicillin & gentamicin
Prosthetic valve - Vancomycin & gentamicin (usually valve replacement required)
IV drug users - Flucloxacillin
How long is IV therapy normally given for in infective endocarditis?
What else should be done?
Monitor cardiac function, temperature & CRP
Consider early referral for surgery if not responding
When should antibiotic prophylaxis for endocarditis be given?
Patients with heart valve lesions, congenital heart defects or prosthetic heart valves:
GI or GU procedures if infection suspected
What is myocarditis?
What are the symptoms and signs?
Inflammation of cardiac muscle.
Fever, chest pain, dyspnoea, palpitations
Arrhythmia, cardiac failure
What are the main causes of myocarditis?
How are they diagnosed?
Enteroviruses - Coxsackie A&B, echovirus
Throat swab, stool sample, serology
How are myocarditis and pericarditis managed?
(Antibiotics and drainage for bacterial pericarditis)