Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CARDIOLOGY > Infective Endocarditis > Flashcards

Infective Endocarditis Flashcards

1
Q

What bacteria can cause an infection in the body after implantation of a cardiac defibrillator device?

A
  • Staph. aureus
  • Staph. epidermidis
  • sp.
  • Propionibacterium acnes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Where can an infection from an implatable cardiac defib. arise anatomically?

A

Biofilm forms on either:

  • Box
  • leads
  • Endocardium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What factors increase the risk of developing infection from an implantable cardiac defib.?

A
  • Complexity of procedure
  • Temporary pacer use
  • Type of device
  • Number of revisions /re-interventions
  • Fever within 24 hours
  • Haematoma post procedure
  • Heart failure, renal failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is infective endocarditis?

A

Infection of the endothelium of the heart valves

  • acute or subacute
  • life threatening
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Hospital acquired cases of infective endocarditis are usually due to which bug?

A

Staph. Aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What predisposing factors put patients at higher risk of developing infective endocarditis?

A

Heart valve abnormality

  • calcification/sclerosis in elderly
  • congenital heart disease
  • post rheumatic fever
  • Prosthetic heart valve

IVDU

Intravascular lines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the pathogenesis of infective endocarditis

A
  • Heart valve damaged
  • Turbulent blood flow over rough endothelium
  • Platelets / fibrin deposited
  • Bacteraemia settle on fibrin/platelet thrombi
    => microbial vegetation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why is infective endocarditis considered life threatening?

A
  • Infected vegetations are friable and break off
    => can become lodged in capillary bed
    => cause abscesses or haemorrhage
    (these consequences can be fatal)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What organisms commonly cause NATIVE valve endocarditis?

A

Staph. aureus
Strep viridans (after dental work)
Enterococcus sp.
Staph. epidermidis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What unusual organisms can cause infective endocarditis?

A
  • Atypical:
    Coxiella, Chlamydia, Legionella, Mycoplasma
- Gram-negatives = HACEK organisms
Haemophilus spp. 
Aggregatibacter spp
Cardiobacterium
Eikenella sp.
Kingella sp.
  • Fungi
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What criteria is used to predict the probability of a patient having endocarditis?

A

Duke Criteria

  • 2 Major
  • 1 Major and 3 minor
  • OR ALL 5 minor criteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How many sets of blood cultures should be taken for infective endocarditis?

A

3 sets of blood cultures
- to prove that bacteria is not a contaminant

If blood cultures are negative
=> consider serology for “atypical” organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

How does acute endocarditis present?

A
  • overwhelming sepsis
  • cardiac failure

=> due to aggressive (virulent) organisms such as Staph. aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What microbiology test distinguishes Staphylococcus aureus from coagulase-negative staph?

A

Coagulase Test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does sub-acute infective endocarditis present?

A 
Fever
malaise
Weight loss
Tiredness
Breathlessness
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What signs may a patient present with in subacute endocarditis?

A
  • fever
  • New/changing heart murmur
  • microscopic haematuria
  • splenomegaly
  • finger clubbing
  • splinter haemorrhages
  • Roth spots
  • Janeway lesions + Osler nodes (THESE ARE PATHOGNOMONIC)
17
Q

What investigation is used to diagnose infective endocarditis?

A
  • ECHO
18
Q

Infection of a prosthetic heart valve can be considered Early or Late. Describe the difference between the two.

A

Early

  • within 60 days of valve insertion
  • due to staph. aureus/epidermidis infection at surgery

Late

  • up to many years later
  • due to coincidental bacteraemia
  • wider range of organisms
19
Q

What empirical antibiotics are used to treat prosthetic valve endocarditis if it can potentially be caused by a variety of organisms?

A

Vancomycin + Gentamicin
+ Rifampicin (couple of days later)

Valve often needs replaced again

20
Q

Endocarditis usually affects which valve in PWIDs

A

Tricuspid

R side of heart

21
Q

Which organism is usually responsible for infective endocarditis in PWIDs?

A

Staph. Aureus

- usually also have septic emboli present

22
Q

What empirical antibiotic treatment is used in patients with Native valve endocarditis?

A
  • Amoxicillin and Gentamicin

- aims to treat Strep viridans (one of most common causes)

23
Q

What antibiotic is used to treat endocarditis in a PWID?

A

Flucloxacillin

- against staph. aureus

24
Q

What SPECIFIC (not empirical) antibiotics can patients be switched onto once their blood cultures return?

A

Viridans strep.
- Benzylpenicillin + gentamicin

Enterococcus sp.
Amoxicillin/Vancomycin + gentamicin

Staph. epidermidis
Vancomycin + gentamicin IV & rifampicin PO

25
Q

How is endocarditis monitored once patients are on antibiotic therapy?

A
  • IV antibiotics for 4 - 6 weeks
  • Monitor cardiac function, temp. and CRP
  • If failing on antibiotic therapy, consider referral for surgery early
26
Q

What is myocarditis?

A
  • inflammation of myocardium

- usually a viral cause (enteroviruses => coxsackie etc)

27
Q

What symptoms and signs do patients present with when they have mycoarditis?

A

Symptoms

  • fever
  • chest pain
  • SOB
  • palpitations

Signs

  • arrhythmia
  • cardiac failure
28
Q

How is myocarditis diagnosed and treated?

A
  • Diagnosed by viral PCR
  • Throat swab (flu) and stool for enteroviruses
  • Supportive treatment
29
Q

What is pericarditis?

A
  • inflammation of outermost layer of heart
  • usually due to viral cause
  • can coexist with myocarditis
  • supportive tx given

CARDIOLOGY (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions