Cardiology - Infective Endocarditis

Question 1

What is infective endocarditis?

Answer 1

Infection of the endothelium of the heart

Affects heart valves most commonly

Question 1

What are the risk factors for infective endocarditis?

Answer 1

IVDU
CKD
Immunocompromised
History of infective endocarditis
Structural heart pathology

Question 2

What structural cardiac pathology can increase risk of endocarditis?

Answer 2

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

Question 3

What organisms can cause infective endocarditis?

Answer 3

Staphylococcus aureus
Streptococcus viridans
Enterococcus faecalis

Question 4

How does infective endocarditis present?

Answer 4

Fever
Fatigue
Night sweats
Muscle aches
Anorexia

Question 5

What are the key examination findings with infective endocarditis?

Answer 5

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

Question 6

What investigations should be done with infective endocarditis?

Answer 6

Blood cultures
- 3 samples 6 hours apart each and taken from different sites
- Gap between repeated sets may be shorter if antibiotics required urgently

Transoesophageal echocardiography
- Vegetations can be seen on valves

In patients with prosthetic heart valves, can be difficult to determine if infection is present in the prosthesis, use special imaging :
18F-FDG PET/CT
SPECT-CT

Question 7

What criteria is used to diagnose infective endocarditis?

Answer 7

Modified Duke criteria

Diagnosis needs:
1 major + 3 minor
5 minor

Question 8

What are the different major and minor criteria for modified duke criteria?

Answer 8

Major
- Persistently positive blood cultures
- Specific imaging findings

Minor
- Predisposition (IVDU)
- Fever
- Vascular phenomena
- Immunological phenomena
- Microbiological phenomena

Question 9

How are patients with infective endocarditis managed?

Answer 9

IV broad spectrum antibiotics e.g. amoxicillin or gentamicin

4 weeks
6 weeks for patients with prosthetic heart valves

Surgery for:
- HF relating to valve pathology
- Large vegetations or abscesses
- Infection not responding to antibiotics

Question 10

What are the key complications of infective endocarditis?

Answer 10

Heart valve damage causing regurgitation
Heart failure
Infective and non-infective emboli
Glomerulonephritis, causing renal impairment