Infective Endocarditis Flashcards Preview

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Flashcards in Infective Endocarditis Deck (31):
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 of normal valves?

Dermatitis
IV injections
Renal failure
Organ transplant
Diabetes
Post-op wounds
Malignancy
SLE
Valve disease, especially regurgitant valves

10

What are the risk factors for IE of prosthetic valves?

Aortic or mitral valve disease

IV drug users are at risk of tricuspid valve problems

Aortic coarctation (narrowing)

11

Which type of organism is usually the culprit of IE?

Bacteria

12

Which type of IE presents acutely? Normal or prosthetic?

Normal

13

Which type of IE presents sub-acutely? Normal or prosthetic?

Prosthetic

14

Which type of people are affected by IE?

The elderly

The young:
- IV drug users
- congenital heart disease

Those with valve prostheses

15

Are more males or females affected by IE?

Females more than males

16

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

17

What is vegetation?

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

18

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

19

How do IE patients present?

Fever

A new heart murmur

Embolic events of unknown origin:

Sepsis of unknown origin

Peripheral stigmata

20

What are the signs/symptoms of an infected embolism?

Stroke
PE
Bone infections
Kidney dysfunction
MI

Abscesses in any part of the body

21

What complications can happen to the vegetation on heart valves?

The vegetation can break off and become an embolus

Causing blockages of other vessels and introducing infection to other parts of the body

22

What are the signs/symptoms of sepsis?

Fever, rigors, night sweats
Weight loss, splenomegaly
Clubbing of fingers
Many more

23

What are the peripheral stigmata of IE?

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

Splinter haemorrhages: tiny haemorrhages under fingernail

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

24

Investigations for IE?

Bloods

Echo: 2 types, look for
Vegetation on heart valve, abscess, new valvular regurgitation

Urinalysis: look for signs of micro haematuria

CXR: cardiomegaly
ECG

25

Describe the 2 types of Echo scan?

Transthoracic (TTE):
Basically an USS of the chest, poorer quality imaging

Trans-oesophageal (TOE):
tube down throat, but good images

26

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

27

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

28

Management of IE?

Anti-microbials: long course via Hickman line

Treat complications: heart failure, arrhythmia, heart block

Surgery: only if really serious

29

Which bacteria are often the culprits of IE?

Strep viridans

Staph aureus / epidermidis

Enterococci

Many more

30

Which fungi are often the culprits of IE?

Candida

Aspergillus

31

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