E: Infective Endocarditis

Question 1

What is infective endocarditis

Answer 1

Infection of the endocardium - usually affecting valve leaflets

Question 2

What is ‘acute’ infective endocarditis

Answer 2

Infective endocarditis in ‘native valves’

Question 3

What is ‘subacute’ infective endocarditis

Answer 3

Infective endocarditis in damaged/diseased valves

Question 4

What is the most common causative organism of infective endocarditis

Answer 4

Streptococcus aureus

Question 5

Why does infective endocarditis occur

Answer 5

Secondary to bacteraemia

Question 6

What may cause bacteraemia

Answer 6

IVDU
Other infections: UTI
Dental procedures
In-dwelling peripheral venous cannula

Question 7

What is the most common cause of sub-acute infective endocarditis

Answer 7

Streptococcus viridian’s

Question 8

In what time does endocarditis of prosthetic valves usually present

Answer 8

within 60d post valve surgery

Question 9

What is streptococcus viridian’s associated with

Answer 9

Dental procedures

Question 10

What may cause staphylococcus epidermis infective endocarditis

Answer 10

peripheral venous cannula

Question 11

What is associated with enterococci infective endocarditis

Answer 11

UTI

GI procedures

Question 12

What is streptococcus bovis infective endocarditis associated with

Answer 12

Increased risk of later developing colorectal cancer

Question 13

When may candida or aspergillum fumigates cause infective endocarditis

Answer 13

HIV patients - immunosuppressed

Question 14

If cultures are negative but other signs are positive for infective endocarditis, what is the likely causative organism

Answer 14

Coxiella Burnetti

Question 15

What are 4 risk factors for acute IE

Answer 15

Diabetes
Skin breach
Renal failure
Immunosuppression

Question 16

What valve is most commonly affected in IVDU patients

Answer 16

Tricuspid

Question 17

How does IE present

Answer 17

Fever and new-onset murmur

Question 18

What ‘hand-sign’ may indicate IE

Answer 18

Clubbing

Question 19

What are 4 signs of immune complex deposition in IE

Answer 19

Oslers nodes
Janeway lesions
Roth spots (retinal haemorrhage)
Microscopic haematuria

Question 20

Explain the pathophysiology of infective endocarditis

Answer 20

Localised infection or contamination causes bacteraemia. Fibrin clots encase the vegetation and cause valve destruction. Bacterial thromboemboli break off and cause subsequent vessel occlusion.

Question 21

What criteria is used to diagnose infective endocarditis

Answer 21

Duke’s Criteria

Question 22

What is Duke’s criteria

Answer 22

States that for a definitive diagnosis of infective endocarditis an individual needs:

• 2 major
• 1 major + 3 minor
• 5 minor

Question 23

What are the 3 ‘major criteria’ involve blood cultures

Answer 23

1. Two organisms consistent with IE from two separate blood cultures
2. More than 3 positive blood cultures taken more than 12h apart
3. Positive culture for coxiella brunette

Question 24

What are 2 other ‘major criteria’ unrelated to cultures

Answer 24

1. Consistent ECHO findings

2. New-onset valvular regurgitation

Question 25

What are the minor criteria

Answer 25

(BIG-TV) 1. Blood Culture not meeting major criteria 2. IVDU and other RF 3. Glomuerlonephritis 4. T > 38 5. Vascular phenomenon - janeway lesions, osler nodes

Question 26

What investigations should be performed in suspected infective endocarditis

Answer 26

1. 3 sets of blood cultures performed on 3 separate occasions at least 12h apart 2. Transthoracic ECHO

Question 27

If a negative trans-thoracic ECHO but strong clinical decision what should be done next

Answer 27

transoesophageal ECHO

Question 28

What does treatment of IE depend on

Answer 28

- prosthetic (or not) valve | - time following surgery

Question 29

What is treatment for IE in native valve or prosthetic valve >1y following surgery

Answer 29

GAF: - Gentamicin - Amoxicillin - Flucloxacillin

Question 30

Why is gentamicin given in IE

Answer 30

As it acts synergistically with flucloxacillin against streptococcus aureus

Question 31

What is treatment for IE with prosthetic valve under 1y

Answer 31

GVR: Gentamicin Vancomycin Rifampicin

Question 32

What prophylaxis should be given to prevent IE in dental surgery

Answer 32

None - prophylaxis for IE is not recommended

Question 33

What is a complication of acute IE

Answer 33

Heart Failure

Question 34

If a patient has undergone a dental procedure and has infective endocarditis, what is the cause

Answer 34

Streptococcus viridian's

Question 35

If a patient has developed infective endocarditis after prosthetic valve surgery, what is the likely causative organism

Answer 35

Staphylococcus epidermis

Question 36

After how long does the spectrum of organisms that can cause infective endocarditis return to normal

Answer 36

2-months