Infective Endocarditis

Question 1

What is infective endocarditis?

Answer 1

Infection of the valves or endocardial lining.

Question 2

Where can the pathogen come from?

Answer 2

• Mouth
• GI tract
• GU tract
• Respiratory tract
• Skin

Question 3

Describe the pathogenesis of IE.

Answer 3

1- Break in the endothelium
2- Platelets adhere to the endothelium (vegetation)
3- Bacteria colonise the vegetations

Question 4

Name the risk factors of IE.

Answer 4

• Prosthetic valves (50% of all cases)
• IVDUs
• Immunocompromise
• Abnormal valve function (AS and MR most commonly)
• Poor dental hygiene

Question 5

Which organisms are most common?

Answer 5

• Strep viridans (by far the most common)
• Strep faecalis
• Staph aureus
• Staph epidermidis (IVDUs)

Question 6

How does IE present?

Answer 6

Expect IE on the background of a new or changing heart murmur:

• Malaise, sweats, myalgia, arthralgia, weight loss, low grade fever

Question 7

What bloods will you do?

Answer 7

• Blood culture and sensitivities
• Inflammatory markers- ESR, CRP, WCC
• FBC- normochromic normocytic anaemia

Question 8

What might a CXR show?

Answer 8

Shadowing due to an embolic pneumonia with infarct (if infection is form resp tract)

Question 9

What may an ECG show?

Answer 9

• MI if there is coronary embolisms

- Conduction defect due to aortic root abscess

Question 10

What might an echo show?

Answer 10

• Vegetation’s
• Paravalvular abscess

*negative ECHO does not exclude IE if it is trans thoracic- TOE is preferred

Question 11

What is the medical treatment of IE?

Answer 11

Empirical ABx:
- See local guidelines

Example:

• Benzylpenicillin (or vancomycin if Allx) PLUS
• Gentamicin (+ fluclox is Staph suspected)

Question 12

What is culture-negative IE?

Answer 12

• IE that has negative blood cultures, normally fungal

- Can also be due to a partially treated bacterial infection

Question 13

What complications are there for IE?

Answer 13

• CHF
• Abscess formation
• Arrhythmia
• Systemic emboli