Infective Endocarditis

Question 1

Which organisms are most commonly associated with IE? (4)

Answer 1

Fungi:
1. Candida

Bacteria:
1. Coxiella burnetti (Q fever)

2. Gram positives:
   a. Staphylococci
   b. Streptococci
3. Gram negatives:
   a. Enterobacteriaceae (coliforms)
   b. Pseudomonas aeruginosa
   c. HACEK organisms

Question 2

Which 2 types of staphylococci are most often associated with IE?

Answer 2

Staph. aureus (including MRSA)

Coagulase negative staphylococci (CoNS)

Question 3

Which 2 types of streptococci are most often associated with IE?

Answer 3

Strep. viridans

Enterococci

Question 4

What are the HACEK organisms?

Answer 4

Haemophilus
Actinobacillus
Cardiobacteria
Eikenella
Kingella

Question 5

What are the 3 types of IE?

List the most common causative bacteria in each one.

Answer 5

Native valve endocarditis (NVE)
-Strep. viridans

Endocarditis in IVDUs
-Staph. aureus

Prosthetic valve endocarditis (PVE)

• Coagulase negative staph. (CoNS)
• Gram negative organisms

Question 6

Clinical features of endocarditis are split into which 2 categories?

Answer 6

Subacute IE

Acute IE

Question 7

What are common causes of subacute endocarditis?

Answer 7

Strep. viridans

Enterococcus

Question 8

Describe the symptoms of subacute endocarditis. (2)

Answer 8

Presentation over weeks-months

Mild toxicity

Question 9

What is the most common cause of acute endocarditis?

Answer 9

Staph. aureus

Question 10

Describe the clinical features of acute endocarditis. Consider:

a) Early features of infection (4)
b) Embolic events (3)
c) Late features of infection (3)

Answer 10

EARLY FEATURES:

• Fever
• Heart murmur
• Fatigue
• Malaise

EMBOLIC EVENTS:

• Small emboli
• Large emboli
• Septic pulmonary emboli

LATE FEATURES:

• Osler’s nodes
• Immunological reaction
• Tissue damage

Question 11

List signs and symptoms caused by emboli in endocarditis. Consider:

a) Small emboli (3)
b) Large emboli (2)
c) Right sided emboli (1)

Answer 11

SMALL EMBOLI:

• Splinter haemorrhages
• Petechiae
• Haematuria

LARGE EMBOLI:

• CVA
• Renal infarction

RIGHT SIDED EMBOLI:
-Pulmonary septic emboli

Question 12

List signs and symptoms caused by immunological reactions, as a late manifestation of endocarditis. (4)

Answer 12

Splenomegaly
Nephritis
Vasculitic lesions of skin and eyes
Finger clubbing

Question 13

List signs and symptoms caused by tissue damage, as a late manifestation of endocarditis. (2)

Answer 13

Valve destruction

Valve abscess

Question 14

Which 3 investigations are used to diagnose endocarditis?

Answer 14

Blood cultures
Echocardiogram
Duke criteria

Question 15

Describe the Duke criteria. Consider:

a) Major criteria (2)
b) Minor criteria (5)

Answer 15

MAJOR CRITERIA:

• 2 separate positive blood cultures
• New valve regurgitation OR positive echo

MINOR CRITERIA:

• Predisposition (heart condition or IVDU)
• Fever (38+)
• Vascular phenomena (e.g. emboli)
• Immunological phenomena (e.g. Osler’s nodes)
• Positive blood cultures which do not meet major criteria

Question 16

How many Duke’s criteria are needed to diagnose endocarditis?

List the different possible combinations for diagnosis. (3)

Answer 16

2 major criteria
1 major and 3 minor criteria
3 minor criteria

Question 17

How long should antibiotic treatment be for endocarditis? Consider:

a) NVE
b) PVE

Answer 17

NVE: 4 weeks

PVE: 6 weeks

Question 18

List 3 indications for surgery in endocarditis.

Answer 18

Heart failure
Uncontrollable infection
Embolism

Question 19

“Uncontrollable infection” is one indication for surgery in endocarditis.

Which 3 criteria define uncontrollable infection?

Answer 19

Abscess formation
Persisting fever PLUS positive blood cultures for 7+ days
Infection caused by multi-drug resistant organisms