Infective Endocarditis & Rheumatic Fever

Question 1

Describe the pathogenesis of bacterial endocarditis and those at risk of developing infective endocarditis

Answer 1

People at risk:
1.Age above 60years
2.Male sex
3.Injection drug use
4. poor dentition or dental infection

more common in older patients with degenerative heart valve disease or with cardiac prosthetic valves. Common organism: virulent Staphylococci

Question 2

Discuss the major aetiological agents of infective endocarditis.

Question 3

● Discuss diagnosis andcomplications of endocarditis.

Question 4

● Describe why a blood culture is the single most important test to diagnose the causative organism and how it should be taken.

Question 5

● Discuss the principles of antibiotic therapy in treatment of infective endocarditis.

Question 6

Discuss concept of prophylactic antibiotics in people with heart defects

Question 7

what is endocarditis ?

Answer 7

inflammation of the inner lining of the hearts chamber and valves

and its life threatening

Question 8

Is Routine dental cleaning a risk factor for Infective endocarditis?

Answer 8

Dental procedures that involve manipulation of gingival tissue or the peripheral region of teeth.

Question 9

Describe the pathogenesis of Infective endocarditis?

Answer 9

In summary, predisposing conditions such as underlying heart disease predispose to endothelial damage of the valves then thrombi is formed. Circulating infective organism will then attach to these thrombi and then proliferate. Vegetations will then be formed. It can embolize and form abscess at distant sites

Question 10

which bacteria is more common in intravenous drug abusers and patients with long-term indwelling catheters e.g.

patient on hemodialysis.

Answer 10

streptococcus Aureus.

Question 11

Blood culture negative organisms include:

Answer 11

mixture of fastidious bacteria, zoonotic bacteria and fungi.

Question 12

HACEK BACTRIA

Answer 12

ORGANISM THAT COLONIZE THENOROPHARYNX.

Question 13

CLINICAL OF INFECTIVE ENDOCARDITIS

Answer 13

fever with chills, loss of appetite and weight loss

heart murmurs
embolic pneumonia.

Question 14

in South Africa most patient IE presents with.

Answer 14

clubbing, splinter haemorrhages and glomerulonephritis

Question 15

when to suspect right sided IE?

Answer 15

often seen in intravenous drug abusers, immunosuppressed patients, patients with indwelling lines or pacemaker leads, has the additional complication of septic emboli to the lungs

Chest X-ray features of septic emboli: “multiple, bilateral areas of opacification with air-fluid levels due to tissue breakdown

Question 16

what is the common cause of right-sided IE

Answer 16

staphylococcus aureus

Question 17

Most common site for infective endocarditis is the

Answer 17

left valve.

Question 18

Diagnosis- Modified Duke Criteria (VERY IMPORTANT

Answer 18

Definite IE= 2 major OR 1 major and 3 minor OR 5 minor

Possible IE= 1 major and 1 minor OR 3 minor

Question 19

what are major criteria

Answer 19

1. positive blood cultures
2. Imaging

Question 20

minor criteria

Answer 20

1.Predisposing heart condition or intravenous drug use
2.Fever > 38°C

3.Vascular phenomena: arterial emboli, splenic infarction, mycotic aneurysms, intracranial haemorrhage and Janeway lesions (including those detected by imaging alone

4.Immunological phenomena: glomerulonephritis,
Osler’s nodes, Roth’s spots & rheumatoid factor

5.Microbiological evidence: positive blood cultures not meeting major criteria above or serological evidence of infection with organism consistent with IE

Question 21

Blood cultures

Answer 21

Microorganisms consistent with IE from two microorganism consistent with IE from two separate blood cultures:

1.viridans group streptococci, Streptococcus bovis group, HACEK group, Staphylococcus aureus; or
Community-acquired enterococci with absence of primary focus
separate blood cultures:

2.viridans group streptococci, Streptococcus bovis group, HACEK group, Staphylococcus aureus; or
Community-acquired enterococci with absence of primary focus

Question 22

Imaging

Answer 22

Transthoracic echocardiography (TTE)- initial choice for both native valve and prosthetic valve IE
Transoesophageal echocardiography (TEE) - better demonstrates complications such as abscess, perforations AND Fistulae

role of echo: detect features suggestive of IE, detect valve abnomarlity

postive role finding: Mobile masses or vegetations on heart valves.

Question 23

Nontender,erythematous papules

Answer 23

Janeways lession

Question 24

The cornerstone of Diagnosis of IE.

Answer 24

positive blood culture.
Echocardiography features.

Question 25

cardiac complication of IE

Answer 25

heart failure
perivascular abscess
pericarditis
intracardiac fistula
>metastatic abscess, spleen, kidney, brain
> Mycotic aneursym

Question 26

Neurologic complication of IE

Answer 26

Embolic stroke
brain abscess or cerebritis
purulent or aseptic meningitis
cerebral haemorrhage
seizures (secondary to abscess or embolic infarction).

Question 27

Renal complication of IE

Answer 27

renal infarction
renal abscess
renal failure

Question 28

Musculoskeletal complication of IE

Answer 28

VERTEBRAL osteomyelitis
septic arthritis.

Question 29

pulmonary complications of IE

Answer 29

most common with right-sided endocarditis

bacterial pneumonia
lung abscess
pyothorax
pleural effusion
pneumothorax.

Question 30

Management - general approach.

Answer 30

Prompt diagnosis and initiation of antimicrobial therapy

Antithrombotic therapy

Need to remove source e.g. infected implanted device

Identify need for early valve surgery

Monitor response to antibiotic therapy

Monitor hemodynamic and cardiac status e.g. surveillance ECGs

Follow-up and prevention of recurrent IE including good dental hygiene, antibiotic prophylaxis