Infective Endocarditis and Rheumatic Heart Disease Flashcards
(104 cards)
1
Q
Infective endocarditis (IE) is an infection of either…..
A
Endocardium Heart valves (prosthetic or native) Interventricular septum Chordae tendinae Intra-cardiac devices
2
Q
What is the endocardium?
A
The inner layer of the heart
3
Q
Which gender gets IE? Which has a worse prognosis?
A
F > M
Females worse prognosis
4
Q
What % of patients with IE have no underlying structural heart disease?
A
25%
5
Q
Who gets IE?
A
Older patients (generative aortic stenosis) Rheumatic heart disease Health care associated Invasive procedures Intra cardiac devices No previously known valve disease Prosthetic valves Mitral valve prolapse Bicuspid aortic valve Congenital heart disease IVDU Immunocompromised
6
Q
Cardiac risk factors for IE
A
MVP VSD AS Rheumatic heart disease Prosthetic heart valve Cardiac surgery for native IE Prior native IE Surgery for prosthetic IE Congenital Heart disease - Cyanotic - teratology of fallot - VSD - PDA - Eisenmenger syndrome - ASD, coarctation of aorta
7
Q
Non cardiac risk factors for IE
A
IVDU Indwelling medical devices DM AIDS Chronic skin infections/burns Genitourinary infections of manipulation including pregnancy, abortion and delivery Alcoholic cirrhosis GI lesions Solid organ transplant Homeless, body live Pneumonia, meningitis Contact with contaminated food or infected farm animals Dog / cat exposure
8
Q
Common organisms causing IE with IVDU
A
Staph aureus CNS B haemolytic strep Fungi Aeorobic gram -ve bacilli Polymicrobial
9
Q
Common organisms causing IE with indwelling medical devices
A
S aureus
CNS
B haemolytic strep
Strep pneumoniae
10
Q
Common organisms causing IE with DM
A
S aureus
B haemolytic strep
Strep pneumoniae
11
Q
Common organisms causing IE with AIDS
A
Salmonella
S pneumoniae
S aureus
12
Q
Common organisms causing IE via chronic skin infections / burns
A
Staph areus
B haemolytic strep
Fungi
aerobic gram -ve bacilli
13
Q
Common organisms causing IE via GU infections
A
Enterococcus GBS Listeria monocytogenes Aerobic gram negative bacilli Neisseria gonnorhoea
14
Q
Common organisms causing IE via alcoholic cirrhosis
A
Bartonella Aeromonas Listeria S pneumonia B haemolytic strep
15
Q
Common organisms causing IE via GI lesions
A
Strep Bovis
Enterococcus
Clostridium septicum
16
Q
Common organisms causing IE via solid organ transplant
A
S aureus
Aspergillus fumigatus
Candida
Enterococcus
17
Q
Common organisms causing IE via homelessness and lice
A
Bartonella
18
Q
Common organisms causing IE via pneumonia or meningitis
A
S pnuemoniae
19
Q
Common organisms causing IE via contact with containerised milk or infected farm animals
A
Brucella
Pasteurella
Coxiella burnetti
Erysipelothrix
20
Q
Common organisms causing IE through dog/cat exposure
A
Bartonella
Patueruella
C septicum
21
Q
Possible pathologies of IE
A
- Adherence and invasion of non bacterial thrombotic endocarditis (a sterile fibrin platelet vegetation)
- Mechanical disruption of valve endothelium due to a variety of factors which favours infection by most types of organisms
- Physically normal endothelium (25%) - local inflammation
22
Q
What can cause mechanical disruption of valve endothelium?
A
Turbulent blood flow/venturi effect Electrodes Catheters Inflammation (rheumatic carditis) Degenerative changes
23
Q
Steps in bacterial colonisation in IE
A
- Exposed stromal cells and extracellular matrix proteins trigger deposition of fibrin-platelet clots to which streptococci bind
- Fibrin adherent streptococci attract monocytes and induce them to protect tissue factor activity (TFA) and cytokines; these mediators activate coagulation cascades, attract and activate blood platelets and induce cytokine, integrin and TFA production from neighbouring endothelial cells, encouraging vegetation growth
- Colonisation of inflamed valve - In response to local inflammation, endothelial cells express integrins that bind plasma fibronectin binding proteins, resulting in endothelial internalisation of bacteria, In response to invasion, endothelial cells produce TFA and cytokines, triggering blood clotting and extension of inflammation, and promoting formation of vegetation, internalised bacteria eventually lyse endothelial cells by secreting membrane active proteins such as haemolysins
24
Q
Causes of transient bacteraemia
A
Brushing teeth
Bowel movements
25
Cardiac conditions at a higher risk of IE
Acquired valvular heart disease (stenosis, regurgitation)
Valve replacement
Structural congenital heart disease (not isolated ASD, fully repaired VSD or PDA, or closure devices that are endothelialised)
Hypertrophic cardiomyopathy
Previous IE
26
Which side of the heart is more affected in ICDU?
Right
27
Presentation of IE
```
FEVER (very common)
Fatigue / malaise
Weight loss
Headache
MSK pain
Altered mentation
MURMUR (very common)
Peripheral stigmata petechiae
Janeway lesions
Oslers nodes
Splinter haemorrhages
Clubbing
Neurological manifestations
Roths spots
Splenomegaly or infarct
Vascular / immunological phenomena
Embolic phenomena
```
28
What vascular / immunological phenomena can be seen in IE?
```
Splinter haemorrhages
Vasculitic rash
Roths spots
Oslers nodes
Janeway lesions
Nephritis
```
29
What is a Vasculitic rash like?
Diffuse
Non blanching
Petechial
Purpuric
30
What are oslers nodes?
```
Deep, red spots
Painful
Raised
Finger pulps
Palms/soles
```
31
What are janeway lesions?
```
Flat, macular
Echymotic
Palms / soles
Non tender
Pathognomonic
```
32
What are the embolic phenomena possibly seen in IE?
```
Focal neurological signs
Peripheral embolus / abscess (30%)
- renal
- cerebral
- splanchnic
- vertebral
Pulmonary embolus/abscess
- right sided IE
```
33
What would give you a high index of suspicion of IE? Fever with......
```
New murmur
Pyrexia of unknown origin
Known IE causative organism
Prosthetic material (PPM, ICD, prosthetic valve, baffle/conduit)
Previous IE
Congenital heart disease
New conduction disorder
Immunocompromised/IVDA
```
34
Diagnosis of IE may be absent in....
Elderly
After antibiotic treatment
Immunocompromised
IE involving less virulent/atypical organisms
35
Markers of infection/inflammation
FBC (neutrophilia)
CRP
ESR
36
What does CRP stand for?
C-reactive protein
37
What does ESR stand for?
Erythrocyte sedimentation rate
38
Investigations for IE
```
FBC, CRP, ESR
U + Es
Blood cultures (prior to Ax)
Urinalysis
ECG
CXR
ECHO
```
39
What blood cultures need to be done?
3 sets from different sites with 6 or greater hours In between
For severe sepsis / septic shock, 2 sets from different sites within 1 hour
40
What would a CXR show in IE?
HF
| Pulmonary abscess
41
Types of ECHO
TTE - transthoracic
| TOE - transoesophageal
42
What % of IE has +ve blood cultures?
85%
43
Causes of IE with -ve blood cultures
Prior Ax Tx
Fastidious organisms (fastidious gram -ve baciili HAEK group, nutritionally variant streptococci)
Intracellular bacteria
44
What are the HACEK group?
```
Haemophilus parainfluenzae
H aphrophilus
H paraphrophilus
H influenzae
Actinobacillus actinomycetemoitans
Cardiobacterium hominis
Eikenella corrodens
Kingella kingae
K dentrificans
```
45
What are the intracellular bacteria that can cause IE? What % of IE is this?
5%
Coxiella burnetti
Bartonella
Chlamydia
46
Most common streptococci causing IE
Strep viridans
47
What is the cause of health care associated IE?
Staph aureus
| Staph epidermidis
48
What bacteria is most likely to cause IE with a native valve?
```
strep viridans (25-65%)
staph aureus (20-48%)
```
49
What bacteria is most likely to cause IE if the patient is an IVDU?
```
staph aureus (50-60%)
B haemolytic strep (10-25%)
```
50
What bacteria is most likely to cause IE if have a prosthetic valve at 2 months?
```
Staph epidermidis (33%)
Staph aureus (22%)
```
51
What bacteria is most likely to cause IE if prosthetic valve present for 2 - 12 months?
Staph epidermidis
52
What bacteria is most likely to cause IE if prosthetic valve present for >12 months?
```
Strep viridans (31%)
Staph aureus (18%)
```
53
What is the criteria used to diagnose IE?
Modified Duke Criteria
54
What is the modified duke criteria?
Major criteria
1. Identifying organism
2. Providing evidence of infection anywhere within the heart
Minor criteria
1. Focus on the endocarditis complex of clinical findings
55
What are the major criteria for the modified duke criteria?
1. Blood cultures +ve for IE
- 2 separate blood cultures with typical organisms consistent with IE
- organisms consistent with IE from persistently +ve blood cultures (all 3 or majority of >4 separate cultures of blood)
- single +ve blood culture for coxiella burnetti
2. Evidence of endocardial involvement
- Positive ECHO
- new valvular regurgitation / murmur
56
What would be involved in a +ve ECHO?
Any endocardial surface, including normal myocardium
Intracardiac / device mass
Para-annular abscess
New dehiscence of prosthetic valve
57
What are the minor criteria for the modified duke criteria?
```
Predisposition
- predisposing heart condition
- Injection drug use
Fever
Vascular phenomena
Immunologic phenomena
Microbiological evidence
```
58
What is a common event that may happen before presenting with IE?
Recent dental appointment
59
What are the vascular phenomena with IE?
```
Major arterial emoboli
Septic pulmonary infarcts
Mycotic aneurysm
Intracerebral haemorrhages
Conjunctival haemorrhages
Janeway lesions
```
60
What are the immunologic phenomena that can occur in IE?
Glomerulonephritis
Oslers nodes
Roth spots
Rheumatoid factor
61
What microbiological evidence would be needed for the minor criteria for IE?
+ve blood cultures (do not meet major criterion)
| Serological evidence of active infection with organism consistent with IE
62
What things in the modified duke criteria mean definite IE?
2 major
1 major and 3 minor
5 minor
63
What things in the modified duke criteria mean possible IE?
1 major
| 3 minor
64
Treatment of IE
Antibiotics IV
| +/- Surgery
65
When should Ax for IE be started?
As soon as blood cultures taken
66
What does the choice of Ax for IE depend on?
```
Have they received prior Ax?
Native or prosthetic valve
Local epidemiology of organisms
Local antibiotic resistance
Specific culture negative pathogens
```
67
What do slow growing, dormant microbes need?
Prolonged therapy - 6+ weeks
| Removal of prosthetic material
68
Treatment of IE if native valve and for how long
Gentamicin and amoxicillin and vancomycin
| 4 WEEKS
69
Causative organisms of IE if native valve
Staph
Strep
HACEK species
Bartonella
70
Treatment of IE if native valve and sepsis
Gentamicin and vancomycin
71
Treatment of IE if prosthetic valve and for how long
Gentamicin and vancomycin and rifampicin
| 6 WEEKS
72
Causative organisms of IE with prosthetic valves
MSSA
MRSA
Non HACEK -ve pathogens
73
Who should rifampicin also be givenfor?
Prosthetic valves
74
S/Es of gentamicin
Ototoxic
| Nephrotoxic
75
Treatment of MSSA causing IE in a native valve and for how long
Flucloxacillin 4 weeks
76
Treatment of MSSA causing IE if prosthetic valve and for how long
Flucloxacillin
Rifampicin
Gentamicin
6 weeks
77
Treatment of IE caused by strep and for how long
Benzylpenicillin 4 - 6 weeks
78
Treatment of IE caused by strep if penicillin allergy and for how long
Vanc 4 - 6 weeks
| Gent > 2 weeks
79
Treatment of IE caused by enterococcus and for how long
```
Amoxycillinn and Gent (4 - 6 weeks)
OR
Gent and BenPen (4 - 6 weeks)
OR if penicillin allergy
Vanc and Gent (4-6 weeks)
```
80
Who are the most worrying group of patients with IE?
Those caused by fungal infection
81
How do patients get IE caused by fungi?
PVE
IVDU
Immunocompromised
82
What does PVE stand for?
Prosthetic valve endocarditis
83
Which fungi cause IE?
Candida
| Aspergillus
84
Mortality of fungi causing IE
Very high (>50%)
85
Treatment of fungi causing IE
Dual anti fungals
| Valve replacement
86
Complications and Indications for surgery in IE
```
HF
Fistula formation
Leaflet formation
Uncontrolled infection
Enlarging vegetation despite Tx
Abscess formation
AV heart block
Embolism
Prosthetic valve dysfunction / dehiscence
Embolism and vegetation > 10mm
Isolated vegetation >15mm
```
87
What would indicate an uncontrolled infection?
```
Persisting fever, + ve blood cultures > 7 - 10 days
Inadequate Ax Tx
Resistant organisms
Infected lines
Locally uncontrolled infection
Embolic complications
Extracardiac site of infection
Adverse reaction to Ax
```
88
What is the most severe form of IE?
PVE
89
Treatment of PVE
Take out prosthetic material
| IV Ax
90
Who gets prophylaxis of IE?
Those at highest risk of IE and at risk of highest adverse outcomes of IE
91
What is important in the prophylaxis of IE?
Good oral hygiene
| Regular dental review
92
Is antibiotic prophylaxis recommended for IE?
NO
93
When should prophylaxis for IE be offered?
An Ax that covers organisms that cause IE
If the person is at risk of IE
Is receiving Antimicrobial therapy
Due to undergoing a GI or GU procedure
At a site where there is suspected infection
94
What % of IE are due to healthcare associated IE?
30%
95
Mortality of IE
9.6 - 265
96
Poor outcomes in IE if....
```
Older
Prosthetic valve IE
Insulin dependent DM
Comorbidity
IVDU
Presence of complications
S aureus, fungi or gram -ve bacilli
ECHO findings - HF, periannular complications
```
97
Criteria for urgent valvular replacement in IE
Severe congestive cardiac failure
Overwhelming sepsis despite Ax therapy (+/- perivalvular abscess, fistulae, perforation)
Recurrent embolic episodes despite Ax therapy
Pregnancy
98
What valve is most commonly affected in IVDUs who have IE?
Tricuspid valve
99
What is an ECG change diagnostic of rheumatic fever?
Prolonged PR interval
100
Why does rheumatic fever occur?
Develops following an immunological reaction to recent (2 - 6 weeks ago) strep pyogenes infection
101
Diagnostic criteria for rheumatic fever
Evidence of recent strep infection
2 major criteria
1 major with 2 minor criteria
102
How can you get evidence of recent streptococcal infection?
Raised or rising streptococci Abs
Positive throat swab
Positive rapid group A streptococcal antigen test
103
Major criteria for diagnosis of rheumatic fever
Erythema marginatum (10% of children, rare in adults)
Syndenhams chorea (often late feature)
Polyarthritis
Carditis and valvulitis (e.g. pancarditits)
Subcutaneous nodules
104
Minor criteria for diagnosis of rheumatic fever
Raised ESR or CRP
Pyrexia
Arthralgia (not if arthritis major criteria)
Prolonged PR interval
