Cardiovascular Flashcards
What two valves are commonly affected in endocarditis?
Mitral and Aortic
What increases your chances of getting endocarditis?
Right side - IVDU Left side - Bicuspid aortic valve - Mitral valve prolapse - Prosthetic valves
Where do IVDUs get endocarditis?
Right side of the heart - generally tricuspid valve
Describe the pathogenesis of infective endocarditis?
The heart valve is damaged in someway which causes endothelial damage leading to platelet and fibrin deposition. If there is a bacteraemia then this settles in this area of damage and causes bacterial endocarditis
What are the most common organisms that cause native valve endocarditis?
Staph aureus Strep viridins Enterococcus Staph epidermidis Also atypical, gram negatives and fungi
If you have an endocarditis cause by gram positive bacteria in clusters what is the cause?
Staph aureus
Which bacteria causes infections in prosthetic valves?
Staph epidermidis
How do enterococcus get into the blood stream to cause endocarditis?
They are usually part of the gut flora - if that becomes very inflamed then they can cross into the blood
How does staph epidermidis get in to cause endocarditis?
- Introduced at the time of heart surgery
2. Infected central line
What kind of bacteria is staph epidermidis?
Gram positive staph
What does coxiella burnetti do?
Causes Q fever and then can cause endocarditis in some individuals. such as immunocompromised Caught from infected animals
What are the gram negative organisms that might cause endocarditis?
HACEK Haemophilus Aggregatibacter Cardiobacterium Eikeleaa Kingella
What are the main symptoms of endocarditis?
Fever and new murmur
What is the modified duke criteria that is used to diagnose endocarditis?
2 major, 1 major and 3 minor, 5 minor
Major
1. Two positive blood cultures from different sites that are positive for organisms that could cause infective endocarditis
2. Evidence of endocardial involvement (positive echocardiogram) for mass, abscess or partial dehisence of a prosthetic valve
Minor
1. IVDU or other predisposing heart condition
2. Fever
3. Vascular phenomena (septic pulmonary infarcts etc)
4. Immunological phenominua (glomerulonephritis, oslers nodes)
5. Microbiological evidence but not meeting major criteria
How many blood cultures do you take for endocarditis?
3 sets from three different sites
