Infective Endocarditis + Rheumatic Heart Disease Flashcards
1
Q
What can infective endocarditis infect?
A
- Infection of inner layer of heart (endocardium)
- Heart valves
- Interventricular septum
- Chordae tendinae
- Intra-cardiac devices
2
Q
What type of heart valves can be affected by infective endocarditis?
A
Both native and prosthetic
3
Q
What is the prognosis for infective endocarditis?
A
- Poor prognosis
- High mortality
4
Q
Why is IE not a uniform disease?
A
- Various presentations
- Possibly dependent on underlying cardiac disease
- Microorganism involved
- Presence/absence of complications
- Underlying patient characteristics
5
Q
Who is involved in the collaborative approach taken towards IE?
A
- Primary care physicians/ acute medicine
- Cardiologists
- Surgeons
- Microbiologists
- Infectious disease
- (Neurologists, neurosurgeons, radiologists, pathologists)
6
Q
What is the incidence of IE?
A
-3-10/100,000
-Males to females 2:1
females have worse prognosis
- ~25% no underlying structural heart disease
7
Q
Why has the epidemiology of IE changed substantially?
A
- Earlier diagnosis
- More acute presentations
- Changes in micro-profile
- Prophylaxis
8
Q
Who is at risk of IE?
A
- Older patients
- Prosthetic valves
- Mitral valve prolapse
- Bicuspid aortic valve
- Congenital heart disease
- IV drug abuse
- Immunocompromised patients
9
Q
What are the cardiac risk factors for IE?
A
- MVP, no murmur
- MVP with MR
- VSD
- AS
- Rheumatic heart disease
- Prosthetic heart valve
- Cardiac surgery for native IE
- Prior native IE
- Surgery for prosthetic IE
10
Q
What specific predisposing valvular lesions are there for IE?
A
- MR
- AR
- AS
- CHD
- Prosthetic valve
11
Q
What CHDs can predispose someone to IE?
A
- Cyanotic heart disease
- Teratology of Fallot
- VSD
- PDA
- Eisenmenger syndrome
- ASD, Coarctation of the aorta
12
Q
What non-cardiac risk factors are there for IE?
A
- Injection drug use
- Indwelling medical devices
- Diabetes mellitus
- AIDS
- Chronic skin infections/burns
- Genitourinary infections or manipulation
- Alcoholic cirrhosis
- GI lesions
- Solid organ transplant
- Homeless, body lice
- Pneumonia/meningitis
- Contact with containerised milk or infected farm animals
- Dog/cat exposure
13
Q
What is included in genitourinary manipulation?
A
- Pregnancy
- Abortion
- Delivery
14
Q
What is the pathophysiology of IE?
A
- Adherence and invasion of nonbacterial thrombotic endocarditis
- Mechanical disruption of valve endothelium
- Physically normal endothelium
15
Q
What is a nonbacterial thrombotic endocarditis?
A
A sterile fibrin platelet vegetation
16
Q
What can cause a mechanical disruption of valve endothelium?
A
- Turbulent blood flow/ Venturi effect
- Electrodes
- Catheters
- Inflammation (rheumatic carditis)
- Degenerative changes
17
Q
What is the pathophysiology of physically normal endothelium involved in IE?
A
Local inflammation
18
Q
What can cause bacteraemia?
A
- Extra-cardiac infections
- Invasive procedures
- Gingival disease
- Activities of daily living
19
Q
What invasive procedures can result in bacteraemia?
A
- Oral, abdominal, genitourinary surgery
- Intravascular catheters
20
Q
What activities of daily living can result in bacteraemia?
A
- Brushing teeth
- Bowel movements
21
Q
What are the classifications of IE?
A
- Acute
- Subacute
- Chronic
22
Q
What is acute IE due to?
A
Staph aureus
23
Q
What is subacute IE due to?
A
Strep
24
Q
What type of IE is more common in IV drug users?
A
Right sided
25
What type of localisations of IE are there?
- Left sided native valve
- Left sided prosthetic valve (early/late)
- Right sided
- Device related
26
What are the modes of acquisition of IE?
- Health care related
- Community acquired
- IVDA
27
What are the types of health care related IE?
- Nosocomial/idiopathic
| - Non-nosocomial
28
What is nosocomial/ idiopathic IE?
Sign/ symptoms >48hrs after hospitalisation
29
What is non-nosocomial IE?
- Signs/symptoms <48hrs after admission/health care contact
- Home based nursing/ IV therapy, haemodialysis <30 days before onset
- Acute care facility <90 days before onset
- Resident in nursing home or long term care facility
30
What 4 indicators are at the start of a diagnosis?
- Variable presentation
- High index of suspicion
- Bacteraemic episode
- Non-specific symptoms (fever, fatigue, malaise)
31
What clinical manifestations of IE are there?
- Fever
- Weight loss
- Headache
- Musculoskeletal pain
- Altered mentation
- Murmur
- Peripheral stigmata petechiae
- Janeway lesions
- Osler's nodes
- Splinter haemorrhages
- Clubbing
- Neurological manifestations
- Roth spot's
- Splenomegaly or infarct
32
What are the signs of IE?
- Congestive heart failure
- Vascular/ immunological phenomena
- Embolic phenomena
33
What are indications of immune complex deposition?
- Splinter haemorrhages
- Vasculitis rash
- Roth spots
- Osler's nodes
- Janeway lesions
- Nephritis
34
What are indications of embolic phenomena?
- Focal neurological signs
- Peripheral embolus/abscess
- Pulmonary embolus/abscess
35
Where may peripheral embolus/abscess occur?
- Renal
- Cerebral
- Spanchnic
- Vertebral
36
When may a pulmonary embolus/abscess occur?
Right side IE
37
Describe vasculitis rash
- Diffuse
- Non-blanching
- Petechial
- Purpuric
38
What are Roth spots?
-Retinal haemorrhages with white/pale centres due to coagulated fibrosis
39
Describe Osler's nodes
- Deep, red spots
- Painful
- Raised
- Finger pulps
- Palms/soles
40
Describe Janeway lesions.
- Flat,macular
- Echymotic
- Palms/soles
- Non-tender
- Pathognomonic
41
Who is included in the high index of suspicion for IE?
- Fever
- New murmur
- Pyrexia of unknown origin
- Known IE causative organism
- Prosthetic material
- Previous IE
- Congenital heart disease
- New conduction disorder
- Immunocompromised/IVDA
42
Who might the signs of IE be absent in?
- Elderly
- After antibiotic treatment
- Immunocompromised
- IE involving less virulent/atypical organisms
43
What investigations are carried out for IE?
- FBC
- CRP
- ESR
- U+Es
- Blood cultures
- Urinalysis
- ECG
- CXR
- ECHO
44
What investigations are markers of infection/inflammation?
- FBC
- CRP
- ESR
45
What can U+Es indicate?
- Nephritis
- Infection
- Sepsis
46
How should blood cultures be carried out for IE?
- Prior to staring antibiotics
- 3 sets
- Different sites
- >6 hrs between
47
How should blood cultures be carried out if the patient has sever sepsis/septic shock?
- 2 sets
- Different sites
- Within 1 hour
48
What is looked for in urinalysis?
+ve blood
49
What is looked for on an ECG?
Conduction delay
50
What is looked for on a CXR?
- Heart failure
| - Pulmonary abscesses
51
What type of ECHO is performed?
TTE +/- TOE
52
When would TOE not be performed for IE?
- Good quality TTE
- Normal TTE
- Low clinical suspicion
53
When would TOE be performed?
- TTE normal
| - High clinical suspicion
54
When is TTE/TOE repeated after 7-10 days?
- TTE/TOE normal
| - Suspicion of IE remains high
55
What happens if TTE is positive?
TOE is performed to look for:
- Complications
- Abscesses
- Measure size of vegetation
56
When would you repeat TTE+TOE with a new complication?
- New murmur
- Persisting fever
- Embolism
- Heart failure
- Abscess
- Atrioventricular block
57
When would you repeat TTE+TOE in uncomplicated IE?
- To assess ongoing treatment for silent complications and vegetation size
- To assess treatment success on complication for valve morphology and cardiac function
58
Why might blood cultures be negative with IE?
- Prior antibiotic treatment
- Fastidious organisms
- Intracellular bacteria
59
What organisms are most IE blood culture positive for?
- Streptococci
- Enterococci
- Staphylococcus
60
What streptococci are most common?
- Oral (viridans)
- S milleri, S anginosus group
- Nutritionally variant defective streptococci recently reclassified
- Group D streptococci
61
Oral (viridans) strep
- S. sanguis
- S. mitis
- S. salivarius
- S. mutans
- Germella morbillorum
62
S milleri, S anginosus group
- S, anginosus
- S. intermedius
- S constellatus
63
Nutritionally variant 'defective' strep recently reclassified
- Abriotrophia
| - Granulicatella
64
Group D strep
- Associated with GIT
| - S. bovine/equinus complex
65
What species of enterococci can be responsible for IE?
- E. faecalis
- E faecium
- E durans
66
What species of staphylococcus can be responsible for IE?
- S. aureus
| - S epidermis
67
Why may there be prior antibiotic treatment
- Antibiotics given for unexplained fever
- Before blood culture taken
- Diagnosis of IE not been considered
- Blood cultures may remain negative for many days after discontinuation of antibiotics
68
If there is prior antibiotic treatment what is most likely to the causative agent of IE?
- Oral strep
| - CNS
69
What organisms are fastidious?
- Nutritionally variant strep
- Fastidious Gram -ve bacilli (HACEK group)
- Brucella
- Fungi
70
Give examples of gram -ve bacilli in the HACEK group.
- H. parainfluenzae
- H. aphrophilus
- H. paraphrophilus
- H. influenza
- Actinobacillus actinomycetemcomitans
- Cardiobacterium hominis
- Eikinella corodens
- Klingella kingae
- K. dentrificans
71
What intracellular bacteria can cause IE?
- Coxiella burnetii
- Bartonella
- Chlamydia
72
How are intracellular bacteria caused IE diagnosed?
- Serological testing
- Cell culture
- Gene amplification
- PCR
73
What is the major criteria of the modified Duke criteria focused on?
- Identifying organism
| - Providing evidence of infection anywhere within the heart
74
What is the minor criteria of the modified Duke criteria focussed on?
The endocarditis complex of clinical findings
75
What would indicate blood cultures positive for IE that fits major modified Duke criteria?
- Typical organisms consistent with IE from 2 separate blood cultures
- Organisms consistent with IE from persistently positive blood cultures
- Single +ve blood culture for Coxiella burnetii (or phase I IgG antibody titre>1:800)
76
What counts as typical organisms consistent with IE?
- Staph aureus
- S viridans
- S bovis
- HACEK
- Community acquired enterococci
77
What would be evidence of endocardial involvement in the major modified Duke criteria?
- Positive ECHO
| - New valvular regurgitation/murmur
78
What would suggest a positive ECHO?
- Any endocardial surface including normal myocardium
- Intracardiac device/mass
- Para-annular abscess
- New dehiscence of prosthetic valve
79
What factors are included in the minor modified Duke criteria?
- Predisposition
- Fever
- Vascular phenomena
- Immunological phenomena
- Microbiological evidence
80
What is included under predisposition in the minor modified Duke criteria?
- Predisposing heart condition
| - Injection drug use
81
What is included under fever in the minor modified Duke criteria?
Temperature >38C
82
What is included under vascular phenomena in the minor modified Duke criteria?
- Major arterial emboli
- Septic pulmonary infarcts
- Mycotic aneurysm
- Intracerebral haemorrhages
- Conjunctival haemorrhages
- Janeway lesions
83
What is included under immunological phenomena in the minor modified Duke criteria?
- Glomerulonephritis
- Osler's nodes
- Roth spots
- Rheumatoid factor
84
What is included under microbiological evidence in the minor modified Duke criteria?
- Positive blood cultures that do not meet the major criteria
- Serological evidence of active infection with organism consistent with IE
85
What is required of the modified Duke criteria for a definite diagnosis?
- 2 major
- 1 major + 3 minor
- 5 minor
86
What is required of the modified Duke criteria for a possible diagnosis?
- 1 major
| - 3 minor
87
What is the treatment for IE?
Antibiotics +/- surgery
88
When should antibiotics be started for IE?
- Started as soon as all blood cultures have taken
| - IV
89
What is the choice of antibiotics dependent on for IE?
- Received prior antibiotics
- Native/prosthetic valve (early/late PVE after surgery)
- Knowledge of local epidemiology, antibiotic resistance and specific culture-negative pathogens
90
What are the antibiotics of choice for native valves?
```
-IV gentamicin (1mg/kg 12 hourly)
AND
-IV amoxicillin (2g 4 hourly)
OR WITH
IV vancomycin (per protocol)
```
91
When would vancomycin be used instead of amoxicillin?
- Penicillin allergy
- Severe sepsis
- MRSA
92
What are the antibiotics of choice for prosthetic valves?
```
-IV gentamicin (1mg/kg 12 hourly)
AND
-IV vancomycin (per protocol)
AND
-Rifampicin (300-600mg IV/PO 12 hourly)
```
93
What is antibiotic choice dictated by?
- Microorganism involved
- Sensitivities
- Resistance
94
How should gentamicin be dosed?
- Dosed to body weight
| - If obese, dose to ideal body weight
95
What are the complications of gentamicin?
- Nephrotoxic
| - Ototoxic
96
When should serum gentamicin levels be carried out?
~4th dose
97
What serum gentamicin levels should be checked?
- Trough (pre-dose) <1mg/L
| - Peak (post-dose) 1hour after dosing 3-5mg/L
98
What investigations should be carried out daily as part of continuing treatment?
- FBC
- U+Es
- CRP
99
What investigation should be carried out every 1-2 days as part of continuing treatment?
-ECG
100
What investigation should be carried out weekly as part of continuing treatment?
ECHO
101
Who is normally affected by IE caused by fungi?
- PVE
- IVDA
- Immunocompromised
102
What fungi can be responsible for IE?
- Candida
| - Aspergillus
103
What is the mortality of IE caused by fungi?
Very high >50%
104
What is the treatment for IE caused by fungi?
- Dual anti-fungals
- Valve replacement
- Often maintained long term, sometimes for life
105
What are the possible complications for IE?
- Heart failure
- Fistula formation
- Leaflet perforation
- Uncontrolled infection
- Abscess formation
- Atrioventricular heart block
- Embolism
- Prosthetic valve dysfunction/dehiscence
106
What indications for surgery are there?
- Heart failure
- Fistula formation
- Leaflet perforation
- Leaflet obstruction
- Uncontrolled infection
- Enlarging vegetation
- Abscess formation
- Atrioventricular heart block
- Prevention of embolism
- Embolism + vegetation>10mm
- Isolated vegetation>15mm
107
What would indicate uncontrolled infection?
- Persisting fever
| - +ve blood cultures> 7-10 days
108
What may be responsible for uncontrolled infection?
-Inadequate antibiotic treatment
-Resistant organisms
-Infected lines
-Locally uncontrolled infection
-Embolic complications
Extracardiac site of infection
-Adverse reaction to antibiotics
109
Why might surgery be carried out for the prevention of embolism?
- Size/mobility vegetation
- Increased size despite antibiotics
- Staph, Strep bovis or Candida
- Previous embolism
- Multivalvular IE
110
What is the most severe form of IE?
PVE
111
What is PVE often associated with?
- Difficulties in diagnosis
- Difficulties with optimal therapeutic strategy
- Poor prognosis
- Removal of prosthetic material
112
What is medical therapy alone associated with?
- High mortality
| - Risk of recurrence
113
What is the recommended treatment for intracardiac devices (prosthetic valves)?
- Removal recommended
- Prolonged antibiotic course
- IV antibiotics for as long as possible prior to removal
- Sterilise device
114
What are the current NICE guidelines on prophylaxis?
- Avoid extensive non-evidence based use of antibiotics
| - Limit prophylaxis to highest risk patients
115
What can transient bacteraemia be caused by?
- After dental/invasive procedures
- Tooth brushing
- Flossing
- Chewing
- Poor dental hygiene
116
Why is prophylaxis not routinely used?
- Huge no. of patients would require it to prevent 1 case of IE
- Majority of patients no potential index procedure can be identified
- Small risk of anaphylaxis
- Emergence of resistance microorganisms
- Lack of scientific evidence for the efficacy of IE prophylaxis
117
What cardiac conditions are at highest risk of IE?
- Acquired valvular heart disease
- Valve replacement
- Structural congenital heart disease
- Hypertrophic cardiomyopathy
- Previous IE
118
What structural congenital heart diseases are not at high risk of IE?
- Isolated ASD
- Fully repaired VSD or PDA
- Closure devices that are endothelialised
119
When should prophylaxis be offered?
- An antibiotic that covers organisms that cause IE
- If a person is at risk of IE
- Is receiving antimicrobial therapy
- Due to under a GI or GU procedure
- At a site where there is suspected infection
120
What advice should be offered when it comes to body piercing/tattooing?
- Education of patients at risk of IE
- Discourage
- If undertaken then should be performed under strict sterile conditions and antibiotic prophylaxis is recommended
121
When are aseptic measures especially important to avoid health care associated IE?
Insertion and manipulation of venous catheters and invasive procedures
