Infective Endocarditis Flashcards Preview

Cardiovascular > Infective Endocarditis > Flashcards

Flashcards in Infective Endocarditis Deck (24):
1

What is infective endocarditis?

Inflammation of the inner tissues of the heart, especially the heart valves

Caused by infectious agents

2

What two symptoms are said to indicate endocarditis until proven otherwise?

Fever + new murmur

3

What types of IE are there?

Native = affects natural valves

Prosthetic = prosthetic valves

Device related: pacemakers, defibrillators etc.

4

Is it more common to get prosthetic IE in your left or right valves?

Left, since its rare to have your right valves replaced

5

Which valves are found on the right side of the heart?

Tricuspid valves
Pulmonary valves

6

Which valves are found on the left side of the heart?

Bicuspid (mitral) valves
Aortic valves

7

What is the difference between early and late prosthetic IE?

Early occurs within a year of operation and the infection is likely to have been introduced during the operation

Late occurs at least a year after the operation. Unlikely to have been introduced during operation

8

What % of cases of IE occur on normal valves?

50%

9

What are the risk factors for IE?

Valve disease
Congenital cardiac disease
IVDU
Invasive IV procedures
Dental procedures
Elderly
Very young

10

Which bug is usually the culprit of IE?

Staph aureus

Strep viridans
Strep A, B, C, D
Staph epidermidis
Pseudomonas
Enterococci

Kingella kingae
Cardiobacterium

11

How do the heart valves end up getting infected?

A damaged valve forms a blood clot

Platelets and fibrin accumulate

Bacteria adhere to the platelet + fibrin site on the heart valve

More and more bacteria accumulate forming lumps of infected fibrin/clot on the valves called vegetation

12

What is vegetation?

A lump of infected fibrin and blood clot hanging off the heart valve

13

What causes heart valve damage?

Altered/turbulent blood flow leading to fibrosis and clot formation

Catheters, electrodes, prostheses etc. that might be inserted into the heart

Solid particles from repeated IV injections

Chronic inflammation: auto-immune conditions

14

How do IE patients present?

Fever

A new heart murmur

Embolic events of unknown origin:

Sepsis of unknown origin

Peripheral stigmata

15

What complications can happen to the vegetation on heart valves?

How might this present?

The vegetation can break off and become an embolus
Causing blockages of other vessels and introducing infection to other parts of the body

Stroke
PE
Bone infections
Kidney dysfunction
MI
Abscesses in any part of the body

16

What are the peripheral stigmata of IE?

Petechiae: small red/purple spot caused by bleeding into the skin

Janeway lesions: non-tender, small red lesions on the palms

Splinter haemorrhages: tiny haemorrhages under fingernail

Osler's nodes: small, painful, red subcutaneous nodules on the pulp of the digits

17

Investigations for IE?

Bloods: FBC, UE, CRP
Blood cultures (during fever)

Echo: transthoracic or trans-oesoph, look for
vegetation on heart valve, abscess, new valvular regurgitation

CXR: cardiomegaly
ECG

18

What blood tests need to be done? And what results might you see?

-FBC:
May see normo-chromic + cytic anaemia
White count is not useful
IgG presence

-U+E

-ESR/CRP
Raised usually

-Microbiology:
Don't always see anything!
3 sets at
3 different times from
3 different sites at peak of fever

19

Why might you not see anything on blood microbiology tests?

Often, the patient presented to their GP with a non-specific infection

The doctor, unsure what the infection was, simply prescribed antibiotics which might have started to kill of bacteria

20

Management of IE?

Anti-microbials: long course via Hickman line
Before cultures: amoxicillin or if severe vancomycin
If prosthetic: vanc + gent + rifamp

Then, depends on bug:
- Staph: fluclox, vanc, rifamp
- Strep: Ben-Pen

Treat complications: heart failure, arrhythmia, heart block

Surgery: only if really serious

21

Which fungi are often the culprits of IE?

Candida
Aspergillus

22

In what situations should you operate in IE?

The infection can't be cured with antibiotics

Complications: severe valve damage, aortic root abscess

To remove infected prostheses

To remove large vegetations before they embolise

23

Diagnostic criteria of IE?

Duke's

Major:
+ve blood cultures on two occasions
+ve findings of IE on ECHO
- mass on valves
- abscess
- new valvular regurgitation

Minor:
- temp over 38
- IVDU or heart structural disease
- Vascular phenomenon: Janeway, splinter + conjunctival haemorrhages
- Immuno phenomenon: Osler's, glomerulonephritis

24

List vascular and immunological phenomena of IE?

Vascular: Janeway lesions, splinter and conjunctival haemorrhages

Immunological: Osler's nodes, glomerulonephritis, rheumatoid factor