Flashcards in Infective Endocarditis Deck (31):
What is infective endocarditis?
Inflammation of the inner tissues of the heart, especially the heart valves
Caused by infectious agents
What two symptoms are said to indicate endocarditis until proven otherwise?
Fever + new murmur
What types of IE are there?
Native = affects natural valves
Prosthetic = prosthetic valves
Device related: pacemakers, defibrillators etc.
Is it more common to get prosthetic IE in your left or right valves?
Left, since its rare to have your right valves replaced
Which valves are found on the right side of the heart?
Which valves are found on the left side of the heart?
Bicuspid (mitral) valves
What is the difference between early and late prosthetic IE?
Early occurs within a year of operation and the infection is likely to have been introduced during the operation
Late occurs at least a year after the operation. Unlikely to have been introduced during operation
What % of cases of IE occur on normal valves?
What are the risk factors for IE of normal valves?
Valve disease, especially regurgitant valves
What are the risk factors for IE of prosthetic valves?
Aortic or mitral valve disease
IV drug users are at risk of tricuspid valve problems
Aortic coarctation (narrowing)
Which type of organism is usually the culprit of IE?
Which type of IE presents acutely? Normal or prosthetic?
Which type of IE presents sub-acutely? Normal or prosthetic?
Which type of people are affected by IE?
- IV drug users
- congenital heart disease
Those with valve prostheses
Are more males or females affected by IE?
Females more than males
How do the heart valves end up getting infected?
A damaged valve forms a blood clot
Platelets and fibrin accumulate
Bacteria adhere to the platelet & fibrin site on the heart valve
More and more bacteria accumulate forming lumps of infected fibrin/clot on the valves called vegetation
What is vegetation?
A lump of infected fibrin and blood clot hanging off the heart valve
What causes heart valve damage?
Altered/turbulent blood flow leading to fibrosis and clot formation
Catheters, electrodes, prostheses etc. that might be inserted into the heart
Solid particles from repeated IV injections
Chronic inflammation: auto-immune conditions
How do IE patients present?
A new heart murmur
Embolic events of unknown origin:
Sepsis of unknown origin
What are the signs/symptoms of an infected embolism?
Abscesses in any part of the body
What complications can happen to the vegetation on heart valves?
The vegetation can break off and become an embolus
Causing blockages of other vessels and introducing infection to other parts of the body
What are the signs/symptoms of sepsis?
Fever, rigors, night sweats
Weight loss, splenomegaly
Clubbing of fingers
What are the peripheral stigmata of IE?
Petechiae: small red/purple spot caused by bleeding into the skin
Splinter haemorrhages: tiny haemorrhages under fingernail
Osler's nodes: small, painful, red subcutaneous nodules on the pulp of the digits
Investigations for IE?
Echo: 2 types, look for
Vegetation on heart valve, abscess, new valvular regurgitation
Urinalysis: look for signs of micro haematuria
Describe the 2 types of Echo scan?
Basically an USS of the chest, poorer quality imaging
tube down throat, but good images
What blood tests need to be done? And what results might you see?
May see normo-chromic & cytic anaemia
White count is not useful
Don't always see anything!
3 sets at
3 different times from
3 different sites at peak of fever
Why might you not see anything on blood microbiology tests?
Often, the patient presented to their GP with a non-specific infection
The doctor, unsure what the infection was, simply prescribed antibiotics which might have started to kill of bacteria
Management of IE?
Anti-microbials: long course via Hickman line
Treat complications: heart failure, arrhythmia, heart block
Surgery: only if really serious
Which bacteria are often the culprits of IE?
Staph aureus / epidermidis
Which fungi are often the culprits of IE?