Endocarditis Flashcards
What is endocarditis
Inflammation of the inner layer of the heart
What is the most common cause of endocarditis
Microbial infection
Where in the heart does endocarditis normally occur
The valves
Give three ways in which microbial infection can enter the bloodstream
Open wound, dental procedure and infected needle
What valves are most commonly affected in normal circumstances
Mitral and aortic
What valve is most commonly affected in IV drug users
Tricuspid
What is non bacterial thrombotic endocarditis (NBTE)
When a thrombus forms on the endothelial layer (usually at the valves)
How does a NBTE form
Endothelial damage occurs, inflammation and/or injury, expose collagen and tissue factor, platelets and fibrin adhere to this and the thrombus is formed
NBTE+bacteraemia=???
Infective endocarditis
What is a vegetation
When bacteria cling on to a thrombus
What are adhesins
Substances produced by bacteria to allow them to stick to the thrombus and other bacteria
What is a biofilm
A matrix surrounding the bacteria
Bacteria attach to high pressure areas
False. Low pressure
What is the most common bacteria cause of endocarditis
viridins streptococci
Describe viridins streptococci
Low virulence, found in mouth, attack previously damaged heart valves, small vegetation and do not destory heart valves
What is the most common bacteria cause of endocarditis in IV drug user
Staphylococcus aureus
Describe staphylococcus aureus
High virulence, found in skin, attack healthy and damaged valves, large vegetation and destroy the heart valve
Describe staphylococcus epidermis
Common in prosthetic valves from previous valve surgery, commonly infects IV catheter and is noscomial
Decribe enterococcus faecalis and streptococcus bovis
Normal gut flora and in a patient with UC or colorectal cancer they can migrate across the gut lining and into the bloodstream
Describe coxiella burnetti
From infected animals and causes Q-fever. This Q-fever can potentially cause endocarditis (months or years later). Usually occurs in patient with high risk factors (immunocomprimised, pregnant, valve defects)
What are the HACEK organisms
Haemophilus, aggregatibacter, cardiobacterium, eikenella, kingella
Describe HACEK organisms
Gram negative, normal mouth and throat flora
What signs of endocarditis do septic emboli cause
Splinter haemorrhages (nails) and janeways lesions (fingers and toes)
What signs of endocarditis do antigen-antibody complex cause
Fingers and toes: Oslers nodes, eyes: roth spots, kidneys: glomerulonephritis
What are painful: Janeways lesions or oslers nodes
Olsers nodes
Other symptoms for endocarditis
Fever and turbulent blood flow murmur
Diagnosis of endocarditis
Positive blood culture and echocardiogram (shows vegetation)
Treatment
Antibiotics or surgery (if severe for examples heart failure)
Prevention of endocarditis
If high risk then antibiotics before dental procedures
Describe libman-sacks endocarditis
Not infection related but related to SLE. The mitral valve is the most commonly affected valve and causes regurgitation. It can also occur on the chordae tendinae, atrial walls and ventricle walls.
