Infective Endocarditis Flashcards
What is Infective Endocarditis?
What type of microorganism?
• Infection of the endocardial surface of heart or valves
• Usually bacterial, occasionally fungal
• Significant morbidity and mortality (20-30%)
• Most commonly runs an insidious course Known as subacute (bacterial) endocarditis (SBE)
• Term ‘infective endocarditis’ preferred (IE)
• Annual incidence in UK 6-7 per 100,000, possibly rising?
Epidemiology - What is causing an increase in IE?
Increasing number of elderly people (and hence abnormal/prosthetic valves)
Increasing number of invasive procedures both diagnostic and therapeutic
Increased number of children with CHD(coronary heart disease) survive
Increase in intravenous drug abuse
Aetiopathogenesis of infective endocarditis
What is endocarditis a consequence of (2)?
Endocarditis usually a consequence of two factors:
- Abnormal cardiac endothelium facilitating bacterial adherence and growth
- Presence of organisms in the blood
Abnormal endothelium which create non-laminar blood flow(Eddy Currents and Jet Streams), promoting fibrin and platelet deposition
Small thrombi allow organisms to adhere and grow
Leads to characteristic infected vegetations
Clinical spectrum
Microbiological spectrum - What organisms are involved in the pathogenesis of infective endocarditis? (4)
Streptococci 63%
Viridans group 50%
Staphylococci 26%
Fungi 4%
Clinical features - signs of infection
- early - fever, sweats, loss of appetite, weight loss, malaise
- late - splenomegaly, clubbing, anaemia
Clinical features - signs of heart disease
- development of a new murmur
- Change to an existing murmur
- Heart failure
Clinical features - signs of embolism?
Clinical features - immune complex?
Signs of embolism:
- septic arthritis, osteomyelitis, splenic abscess
- CNS - meningitis, miliary brain abscess, TIA, stroke
Immune Complex:
- Skin - Osler’s nodes , Splinter haemorrhage
- Renal - haematuria
- Eyes - Roth’s spots
Investigations
Treatment of infective endocarditis?
Bactericidal Antibiotics
Surgery when - Extensive damage to a valve / embolisation / infection of prosthetic material / worsening renal failure / persistent infection but failure to culture an organism / large vegeatations
Prognosis -when is prognosis worse?
Worse when :
- organism cannot be identified
- cardiac failure
- infection occurs on a prosthetic valve
- microorganisms are resistant to therapy
What is prophylaxis?
(From google)
Treatment given to PREVENT a disease
Is antibiotic prophylaxis recommended?
Antibiotic prophylaxis against infective endocarditis is NOT recommended routinely[1]:
• for people undergoing dental procedures
Prophylaxis - infective endocarditis
Who are the patients most at risk?
• Adults and children with structural cardiac defects at risk of developing infective endocarditis
• Acquired valvular heart disease with stenosis or regurgitation
• Hypertrophic cardiomyopathy
• Previous infective endocarditis
• Structural congenital heart disease
• Valve replacement
Prophylaxis - patient advice
Should offer patients at increased risk of infective endocarditis information about prevention, eg:
• benefits and risks of antibiotic prophylaxis, and an explanation of why antibiotic prophylaxis is no longer routinely recommended
• the importance of maintaining good oral health
• symptoms that may indicate infective endocarditis and when to seek expert advice
• the risks of undergoing invasive procedures, including non-medical procedures such as body
piercing or tattooing.
