Infective Endocarditis

Question 1

What is infective endocarditis. (2)

Answer 1

Infection of the endothelium.

Usually involves the valves.

Question 2

What are the vegetations found in infective endocarditis composed of. (3)

Answer 2

They are a mixtures of bacteria, fibrin and platelets.

Question 3

What are the causes of infective endocarditis. (3)

Answer 3

Bacteria.
Fungi.
Other.

Question 4

What is the most common bacteria involved in IE in IVDU.

Answer 4

Streptococcus viridans.

Question 5

What percentage of IE have no identified causative organism.

Answer 5

Approximately 10%.

Question 6

What bacteria are involved in IE. (5)

Answer 6

Staphylococcus aureus/epidermidis. 
Streptococci viridans. 
Enterococci. 
Chlamydia. 
Gram negative bacteria (rarely: haemophilus, actnobacillus, cardiobacterium, eikenella, kingella).

Question 7

What two categories is IE divided into.

Answer 7

Acute endocarditis.

Subacute endocarditis.

Question 8

What is the difference between acute endocarditis and subacute endocarditis. (2)

Answer 8

Acute endocarditis is a rapidly progressive illness.

Subacute endocarditis is a slowly progressive condition.

Question 9

What are the symptoms of IE. (4)

Answer 9

Fever.
Anorexia.
Weight loss.
Myalgia.

Question 10

What is Duke’s criteria for IE.

Answer 10

It is a way of diagnosis IE.

Question 11

What aspects of Duke’s criteria are needed to positively diagnose IE. (3)

Answer 11

2 major criteria.
1 major criteria and 3 minor criteria.
5 minor criteria.

Question 12

What are the major criteria of Duke’s criteria for IE. (2)

Answer 12

Blood culture positive for typical organism or persistently positive.
Evidence of endocardial involvement.

Question 13

What are the minor criteria of Duke’s criteria for IE. (5)

Answer 13

Fever.
Previous heart condition or IVDU.
Immunological phenomena: osler’s nodes, roth spots, glomerulonephritis, clubbing, petechia, arthralgia.
Vascular phenomena: mocotic aneurysms, Janeway lesions, septic emboli, intracranial haemorrhage, visceral infarct, splinter haemorrhages.
Positive blood culture with atypical bacteria.

Question 14

What are osler’s nodes.

Answer 14

Raised tender nodules on finger pulps.

Question 15

What are roth spots.

Answer 15

Small boat shaped retinal haemorrhages with a pale centre.

Question 16

What are Janeway lesions.

Answer 16

Painless macules on the palm or sole of feet.

Question 17

What is fever+new murmur until proven otherwise.

Answer 17

Infective endocarditis.

Question 18

When should you take blood cultures in a patient presenting with a fever.

Answer 18

Any fever lasting >1week in those known to be at risk of developing IE.

Question 19

Where do 50% of all endocarditis occur.

Answer 19

In normal valves.

Question 20

How does infective endocarditis typically present. (3)

Answer 20

It follows an acute course.

Presents with acute heart failure and emboli.

Question 21

What are the risk factors for developing acute IE. (6)

Answer 21

Dermatitis. 
IV injections. 
Renal failure. 
Organ transplantation. 
DM. 
Post-op wounds.

Question 22

What is the usual via of entry for acute IE.

Answer 22

Via the skin.

Question 23

What is the mortality rate for acute presentations of endocarditis.

Answer 23

5-50%.

Question 24

What is the mortality rate for acute endocarditis related to. (2)

Answer 24

Age and embolic events.

Question 25

Where does subacute endocarditis tend to occur.

Answer 25

On abnormal valves.

Question 26

What are the risk factors for developing subacute endocarditis. (6)

Answer 26

``` Aortic or mitral valve disease. Tricuspid valves in IVDU. Coarctation. Patent ductus arteriosus. VSD. Prosthetic valves. ```

Question 27

What are the two aetiologies of IE on prosthetic valves. (2)

Answer 27

Early (during surgery). | Late (haematogenous).

Question 28

What are some fungal causes of IE. (3)

Answer 28

Candida. Aspergillus. Histoplasma.

Question 29

What are the other causes of IE. (2)

Answer 29

SLE. | Malignancy.

Question 30

What are the clinical signs of IE due to. (4)

Answer 30

Septic signs. Cardiac lesions. Immune complex deposition. Embolic phenomena.

Question 31

What are the septic signs of IE. (8)

Answer 31

``` Fever. Rigors. Night sweats. Malaise. Weight loss. Anaemia. Splenomegaly. Clubbing. ```

Question 32

What are the cardiac lesion signs of IE. (2)

Answer 32

Any new murmur. | Any change in a pre-existing murmur.

Question 33

What is a common cause of death in IE.

Answer 33

Left ventricular failure.

Question 34

What are the immune complex deposition signs of IE. (7)

Answer 34

``` Vasculitis. Acute renal failure. Roth spots. Slinter haemorrhages. Osler's nodes. Glomerulonephritis. Microscopic haematuria. ```

Question 35

What are the embolic signs of IE.

Answer 35

Emboli may cause abscesses in the relevant organ (brain, heart, kidney, spleen, gut, lung, skin - Janeway lesions).

Question 36

What is the mortality rate of IE. (3)

Answer 36

30% with staphs. 14% if bowel organisms. 6% if sensitive streptococci.

Question 37

What are the ECG changes associated with IE.

Answer 37

long PR interval at regular intervals.

Question 38

What may be seen on the blood tests of a patient with IE. (3)

Answer 38

Normocytic normochromic anaemia. High ESR/CRP. Neutrophilia.