Infective Endocarditis Flashcards
What is infective endocarditis?
Infection of the endocardium and the valves, associated with significant morbidity and mortality due to cardiac and extracardiac manifestations
What makes normal heart valves more susceptible to bacterial colonization in infective endocarditis?
Damage to normal heart valves allows platelet and fibrin deposits on the damaged endothelium for bacterial adhesion
What are some causes of damage to heart valves that lead to infective endocarditis?
Degeneration, instrumentation, contact with solid particles from injection drug use
What is the susceptibility of prosthetic heart valves in infective endocarditis?
Prosthetic heart valves are susceptible to bacterial adhesion and biofilm formation
What is heart valve vegetation?
Irregular growths of microorganisms and cell debris forming a vascular mass attached to the valve
What complications can vegetations cause in infective endocarditis?
Valvular stenosis or regurgitation
What can occur if vegetations extend to the perivulvar area?
Formation of abscesses that induce heart block, most common with aortic valve
What are the embolic risks associated with left-sided vegetations?
Prone to forming emboli in systemic circulation
What are the embolic risks associated with right-sided vegetations?
Prone to forming emboli in pulmonary circulation
What does the acronym ‘I HAVE ABC’ represent in the context of infective endocarditis microorganisms?
Significant microorganisms of infective endocarditis: I HAVE ABC
HA: HACEK group (Haemophilius, aggregatibacter, cardiobacterium, eikenella, kingella)
V: Vridans group streptococci
E: Enterococcus spp.
A: Staphylococcus aureus
B: Streptococcus bovis
C: Coxiella burnetii
What are the common microorganisms causing infective endocarditis?
Most cases caused by Staphylococcus or streptococcus species
Which microorganism is commonly associated with infective endocarditis in drug users?
Staphylococcus aureus
What is the common flora associated with non-vegetative endocarditis (NVE)?
Oral flora, e.g., Virdans group streptococci
What microorganisms are typically involved in healthcare-associated infective endocarditis?
Staphylococcus aureus, enterococci
Which microorganisms are associated with prosthetic valve endocarditis (PVE)?
Staphylococcal species
What microorganisms are commonly found in culture-negative infective endocarditis?
Gram-negative HACEK group, coxiella, brucella, bartonella
What is the most common symptom of infective endocarditis?
Fever
What are other common symptoms of infective endocarditis? FROM JANE
F: Fever (most common symptom)
R: Roth spots: Red lesions with white or pale centres that form due to retinal haemorrhaging
O: Osler nodes: Tender raised, red-purple lesions on the hands or feet, usually near fingers and toes
M: Murmur: Either a new murmur or changing murmur eg. aortic regurgitation murmur
J: Janeway lesions: Non-tender, haemorrhagic lesions (bleeding into the skin) that occur mostly on the palms and soles on the thenar and hypothenar eminences
A: Anaemia
N: Nail-bed haemorrhaging (splinter haemorrhaging)
E: Emboli
What are Roth spots?
Red lesions with white or pale centres that form due to retinal haemorrhaging
What are Osler nodes?
Tender raised, red-purple lesions on the hands or feet, usually near fingers and toes
What does a murmur indicate in infective endocarditis?
Either a new murmur or changing murmur, e.g., aortic regurgitation murmur
What are Janeway lesions?
Non-tender, haemorrhagic lesions that occur mostly on the palms and soles
What is a common hematological finding in infective endocarditis?
Anaemia
What is nail-bed haemorrhaging also known as?
Splinter haemorrhaging
What does emboli refer to in the context of infective endocarditis?
The presence of emboli in the bloodstream
What is the first-line radiological investigation for infective endocarditis?
Transthoracic Echocardiography (TTE) to identify vegetations
When should Transesophageal Echocardiography (TEE) be used?
In patients with negative TTE and known significant risk factors or high clinical suspicion
What should be done if a TTE is positive and there is a high risk of complications?
Perform TEE to assess the need for valve surgery
What is the first-line lab investigation for infective endocarditis?
Three sets of blood cultures drawn from different venipuncture sites
What is important about the timing of blood cultures?
The first and last cultures should be at least 1 hour apart
What additional testing may be performed in the lab for infective endocarditis?
Serological testing for microorganisms
Give 5 other symptoms associated with fever in IE?
Malaise, myalgia, headaches, dyspnea, night sweats
What criteria is used to diagnose infective endocarditis (IE)?
Duke criteria is used to determine possible or definite IE diagnosis.
What constitutes a definite IE diagnosis?
2 major OR 1 major and 3 minor OR 5 minor criteria fulfilled.
What constitutes a possible IE diagnosis?
1 major and 1 minor OR 3 minor criteria fulfilled.
What are the major criteria for IE diagnosis?
B: Blood cultures positive in 2 separate cultures 12 hours apart
E: Echocardiographic evidence of endocardial involvement
What are the minor criteria for IE diagnosis?
T: Temperature over 38 degrees Celsius
I: Immunological phenomena: Osler nodes, Roth spots
M: Microbiological evidence that doesn’t meet major criterion
E: Embolic phenomenon: Major arterial emboli, septic pulmonary infarcts, mycotic aneurysm, intracranial hemorrhage, conjunctival hemorrhage, Janeway lesions
R: Risk factors
What is the management for infective endocarditis?
- Prolonged course of IV bactericidal antibiotics
- Indications for surgical valve replacement: V-HEARTS
- Antibiotic prophylaxis for high-risk individuals.
What is the recommended duration of IV antibiotics for native valve endocarditis (NVE)?
4-6 weeks course.
What is the recommended duration of IV antibiotics for prosthetic valve endocarditis (PVE)?
6 weeks course.
What does V-HEARTS stand for in surgical valve replacement indications?
V: Vegetation
H: Heart failure
E: Enterococcal endocarditis
A: Abscess, annular or aortic
R: Rhythm abnormalities or heart block
T: Treatment failure (e.g., fungal endocarditis, persistent positive cultures)
S: Surgical intervention needed.
What is the first-line antibiotic prophylaxis for high-risk individuals before invasive dental procedures?
2 g oral amoxicillin 30 to 60 minutes prior to the procedure.
