Infective endocarditis

Question 1

What is infective endocarditis

Answer 1

Any infectious vegetation on a heart valve

-Pyrexia with a new or changing murmur

Question 2

Who gets it

Answer 2

Damaged endocardium

• Damaged valves
• prosthetic valve
• Congenital heart disease

High levels of sustained bacteraemia

• Intravenous drug users
• Infected intravascular devices
• Untreated abscess/collection elsewhere

Question 3

What are the most likely causative organism in those with their own heart valves

Answer 3

Streptococcus viridians
Strep minis
Staph aureus

Question 4

Most likely causative organism in those with prosthetic valves

Answer 4

Coagulase negative staph such as staph epidermis

Question 5

Most likely causative organism in those with IVDU

-Which sided valve is more likely infected

Answer 5

Staph aureus (as on skin)
-Right sided as coming from skin so first valve it hits

Question 6

MOSt likely causative organism in those with manipulation of GU or GI tract

Answer 6

Enterococcus

Question 7

What causes non infectious endocarditis and what does it cause

Answer 7

Systemic lupus erythematosus

-Libman-Sacks lesions

Question 8

Textbook features of infective endocarditis

Answer 8

Murmur
Anaemia
Janeway lesions (vascular phenomenon. Irregular, erythematous, flat, painless macules on palms and soles)
Osler’s nodes (painful red lesions on hands and feet)
Roth’s spots (in retina)

Pyrexia
Emboli (stroke, pulmonary, splenic, renal infarcts. Gangrene of fingers)
Nail haemorrhages (splinter)

Question 9

How to make a diagnosis

Answer 9

Duke’s criteria

Question 10

What is dukes criteria

Answer 10

You need either:
2 major and 1 minor
1 major and 3 minor
5 minor

Major Criteria
Typical organism from 2 x separate or persistently +ve BCs
Echo findings
New valvular regurgitation (worsening or changing of pre-existing murmur not sufficient).

Minor criteria
Predisposition (heart condition, IVDU)
Fever >38 degrees C
Vascular phenomena
Immunologic phenomena (Roth spots, glomerulonephritis)
Positive BC (but not meeting major criterion)

Question 11

Complications of staph aureus

Answer 11

Heart failure
Peri-valvular disease
Septic emboli
Metastatic abscess (e.g. lung)
Mycotic aneurysm

Question 12

Management of infective endocarditis

Answer 12

Abx
Empirical choice depends on prosthetic vs native valve and clinical condition

Surgical
Excision of infected or damaged valve and replacement with prosthetic
Draining of metastatic abscess