Infective endocarditis

Question 1

What are the risk factors for infective endocarditis?

Answer 1

IVDU
Structural heart pathology
CKD
Immunocompromised
History of infective endocarditis

Question 2

What structural pathologies are associated with infective endocarditis?

Answer 2

Valvular heart disease
Congenital heart disease
Hypertrophic cardiomyopathy
Prosthetic heart valves
Implantable cardiac devices

Question 3

Which valve is most commonly affected by IE?

Answer 3

Mitral valve

Question 4

Which valve is most commonly affected by IE associated with IVDU?

Answer 4

Tricuspid valve

Question 5

What are the bacterial causes of IE?

Answer 5

Staphylococcus aureus - most common
Staphylococcus epidermidis - associated with indwelling lines and prosthetic valves
Streptococcus viridans - associated with poor dental hygeine
Enterococcus

Question 6

What are the symptoms of IE?

Answer 6

Fever
Headache
SOB
Night sweats
Fatigue
Weight loss
Muscle aches

Question 7

What are the key examination findings in IE?

Answer 7

New heart murmur
Splinter haemorrhages
Petechiae
Janeway lesions
Osler’s nodes
Roth spots
Splenomegaly
Finger clubbing

Question 8

What investigations are required for a diagnosis of infective endocarditis?

Answer 8

Three blood cultures
- Separated by 6 hours
- Taken from different sites
- Ideally taken before starting antibiotic therapy

Echocardiogram (TTE is first line)

Question 9

What investigations are useful in infective endocarditis?

Answer 9

Inflammatory markers - raised CRP, raised WCC
CXR - exclude other causes of dyspnoea
12 lead ECG

Question 10

What are the Duke criteria?

Answer 10

Requires one major plus three minor criteria or five minor criteria

Major criteria:
- Persistently positive blood cultures
- Specific imaging findings

Minor criteria:
- Predisposition
- Fever
- Vascular phenomena
- Immunological phenomena
- Microbiological phenomena

Question 11

What is the first line management of infective endocarditis?

Answer 11

IV antibiotics - amoxicillin and gentamicin
- 4 weeks for native heart valves
- 6 weeks for prosthetic heart valves

Question 12

What is the second line management of infective endocarditis?

Answer 12

Surgery to remove infected tissue and repair or replace affected valves

Question 13

What are the complications of infective endocarditis?

Answer 13

Congestive heart failure
Septic embolisation
Valvular rupture
Glomerulonephritis