36. Infective Endocarditis and Rheumatic Heart Disease Flashcards
1
Q
What is infective endocarditis?
A
- infection of the inner layer of the heart (endocardium)
2
Q
What structures does infective endocarditis affect? (4)
A
- heart valves (native or prosthetic)
- interventricular septum (septal defects)
- chordae tendinae
- intra-cardiac devices
3
Q
What is the prognosis for infective endocarditis like?
A
- Getting worse (mortality rate is 30%=high)
- poor prognosis generally
- could be due to increased use of antibiotics, increased IV drug abuse and more patients undergoing cardiac surgeries
4
Q
Is infective endocarditis a uniform procedure? Why? (5)
A
- Not uniform procedure
- Depends on which presentation, underlying cardiac disease, microorganism involved, presence/absence of complications, underlying patient characteristics
5
Q
Which health professionals are often involved in the care for infective endocarditis patients? (6)
A
- primary care physicians/ acute medicine
- cardiologists
- surgeons
- microbiologists
- infectious disease team
- neurologists, radiologists, pathologists etc
6
Q
What is the general prevalence of infective endocarditis?
A
- 3-10/100,000 in general population
- more common among elderly
- more common in males
- females worse prognosis
- ~25% don’t have underlying structural heart disease
7
Q
What was infective endocarditis seen as previously? (4)
A
- presented in young adults
- well defined valve disease
- mostly rheumatic valve disease
- more chronic/subacute course
8
Q
Why has changed in epidemiology of infective endocarditis? (4)
A
- earlier diagnosis
- more acute presentation
- changes in micro profile
- prophylaxis (conflicting recommendations)
9
Q
What patients are more at risk of infective endocarditis NOW? (7)
A
- older patients (with degenerative aortic stenosis)
- prosthetic valve patients
- mitral valve prolapse patients
- bicuspid aortic valve patients
- congenital heart disease
- IV drug abusers
- immunocompromised patients
10
Q
What is happening nowadays to rheumatic heart disease cases?
A
They are decreasing (<20%), infective endocarditis is due to other causes nowadays
11
Q
What is rheumatic heart disease?
A
- chronic heart condition caused by rheumatic fever (it’s a complication of rheumatic fever)
- inflammation causes heart valves to inflame and stiffen as they are damaged
- affects blood flow through the heart
12
Q
What might affect the change in how infective endocarditis is seen nowadays and how it presents? (4)
A
- health care associated
- invasive procedures on the rise
- intra cardiac devices
- no previously known valve disease
(or possibly increased use of antibiotics or IV drug use)
13
Q
What are biggest cardiac risk factors for infective endocarditis? (8)
A
- rheumatic heart disease
- prosthetic heart valve
- surgery for prosthetic
infective endocarditis - prior native or surgery for infective endocarditis
- aortic stenosis
- ventricularseptal defect
- mitral valve prolapse (with mitral regurgitation)
- mitral valve prolapse (with no murmur)
14
Q
What are specific predisposing valvular lesions for infective endocarditis? (5)
A
- mitral regurgitation
- aortic regurgitation
- aortic stenosis
- congenital heart disease
- prosthetic valve
15
Q
What are common congenital heart disease which predispose patient to infective endocarditis? (6)
A
- cyanotic heart disease
- tetralogy of Fallot
- ventricular septal defects
- patent ductus arteriosus
- Eisenmenger syndrome
- ASD (atrial septal defect), coarctation of the aorta
16
Q
What are non-cardiac risk factors for infective endocarditis? (13)
A
- IV drug use
- indwelling medical devices
- diabetes mellitus
- AIDS
- chronic skin infections, burns
- genitourinary infections or manipulation, including pregnancy, abortion, delivery
- alcohol cirrhosis
- gastrointestinal lesions
- solid organ transplant
- homeless, body lice
- pneumonia or meningitis
- contact with contaminated milk or farm animals
- dog/cat exposure
17
Q
What is the pathophysiology behind infective endocarditis?
A
- endothelial damage occurs to endothelium
- damage can result due to turbulence (pulmonary stenosis, bicuspid aortic valve or mitral valve prolapse) or due to high pressure interfaces (e.g. VSD or PDA or coarctation of aorta)
- formation of fibrin-platelet aggregation/ growth
- invasion of nonbacterial thrombotic endocarditis occurs which then leads to bacteria becoming entrapped
18
Q
What factors can cause mechanical disruption of valve endothelium?
A
- turbulent blood flow/ Venturi Effect
- high pressure interfaces
- electrodes
- catheters
- inflammation (rheumatic carditis or degenerative changes)
- infection by most types of organisms
19
Q
What is the most common pathophysiological feature of infective endocarditis in terms of epithelium?
A
- local inflammation seen in most
- physically normal endothelium only in ~25% cases
20
Q
What factors lead to bacteraemia which can eventually lead to infective endocarditis?
A
- extra-cardiac infections
- invasive procedures (oral, abdominal, genitourinary surgery or intravascular catheters)
- gingival disease (gum disease)
- daily activities (brushing teeth, bowel movements)
21
Q
What are 3 main classifications of infective endocarditis?
A
- acute
- subacute
- chronic
22
Q
What are different types of infective endocarditis localisation which affects its classification? (4)
A
- left sided native valve
- left sides prosthetic valve
- right sided
- device related (PPM, ICD)
23
Q
What are different modes of acquisition of infective endocarditis?
A
- health care related (nonsocomial/hosp.acquired >48hrs after hospitalisation or non-nosocomial with signs and symptoms <48 hours after admission)
- community acquired
- IV drug abuse
24
Q
What are the general symptoms of infective endocarditis? (6)
A
Variable presentation:
- bacteraemic episode
- fever (non-specific)
- fatigue (non-specific)
- malaise (non-specific)
- anorexia and weight loss
- sweats
- rigors
25
What are general signs of infective endocarditis? (6)
1. congestive heart failure
2. vascular/ immunological phenomena: immune complex deposition
3. embolic phenomena: thromboembolism
4. clubbing
5. heart murmur
6. splenomegaly
26
What signs does immune complex deposition lead to? (6)
1. splinter haemorrhages
2. vasculitic rash
3. Roth Spots
4. Osler's nodes
5. Janeway lesions
6. nephritis
27
What signs does thromboembolism like symptoms lead to in infective endocarditis? (3)
1. focal neurological signs
2. peripheral embolus (30%) or abscess (renal, cerebral, splanchnic and vertebral)
3. pulmonary embolus or abscess (right sided infective endocarditis)
28
What are features of a vasculitic rash? (4)
- diffuse
- non-blanching
- petechial (small, 1-2mm)
- purpuric
29
What are features of roth spots? (3)
- retinal haemorrhages
- white/pale centre
- coagulated fibrosis
30
What are features of Osler's nodes? (5)
- deep, red spots
- painful
- raised
- finger pulps
- palms and soles affected
31
What are features of Janeway lesions? (6)
- flat and muscular
- echymotic (escape of blood into tissues from ruptured blood vessels)
- palms and soles affected
- non-tender
- pathognomonic (characteristic)
32
What features ADDITIONALLY to the fever make the fever a suspicion for possible infective endocarditis? (8)
1. new murmur
2. pyrexia of unknown origin
3. known infective endocarditis causative origin
4. prosthetic material ( PPM, ICD;implantable cardioverter defibrillator, prosthetic valve, baffle/conduit)
5. previous infective endocarditis
6. congenital heart disease
7. new conduction disorder
8. immunocompromised/ IV drug user
33
In which patients might signs of infective endocarditis be absent? (4)
1. elderly
2. after antibiotic treatment
3. immunocompromised
4. infective endocarditis involving less virulent/ atypical organisms
34
What investigation should be done to diagnose infective endocarditis? (6)
1. marker of infection/inflammation (FBC, CPR, ESR, U+Es,)
2. Urinalysis (+ve blood)
3. blood cultures
4. ECG (conduction delay)
5. chest x ray (heart failure, pulmonary abscess)
6. echocardiogram
35
What markers of infection/inflammation should be looked for in infective endocarditis? (4)
1. full blood count ( looking for neutrophilia)
2. CRP; C reactive protein (present in inflammation)
3. ESR; erythrocyte sedimentation rate (present in inflammation)
4. U+Es (urea and electrolytes); checks for nephritis, infection, sepsis
36
What blood cultures should be taken PRIOR to starting antibiotics?
- 3 sets
- from different sites
- >=6 hours between
37
What blood cultures should be taken during severe SEPSIS/ septic shock?
- 2 sets
- from different sites
- within 1 hour
38
What is checked for in urinalysis to diagnose infective endocarditis? (2)
- microscopic haematuria (red cell casts in urine)
- proteinuria
(present in at least 50% patients)
39
What is seen on ECG ininfective endocarditis?
conduction delay
40
What is seen on a chest x ray in infective endocarditis?(2)
1. heart failure
| 2. pulmonary abscesses
41
What two types of echo need to be done for infective endocarditis? (2)
1. transthoracic (TTE)
| 2. transoesophageal (TOE)
42
What echo is the FIRST line imaging that should be used?
TTE first (transthoracic)
43
What to do if TTE echo is normal?
-low clinical suspicion and therefore TOE not needed
44
What to do if TTE echo is abnormal if there is a positive test/suspicion?
```
TOE needed:
- complication
- abscesses
- measure size of vegetation
(all investigated)
```
45
What to do if TTE and TOE are normal but suspicion of infective endocarditis remains high?
repeat TTE and TOE at 7-10 days
46
What are new complications which can arise in repeat TTE and TOE related to infective endocarditis? (6)
1. new murmur
2. persisting fever
3. embolism
4. heart failure
5. abscess
6. atrioventricular block
47
What needs to be assessed if repeat TTE and TOE is done and uncomplicated infective endocarditis is suspected? (2)
1. Asses ongoing treatment (e.g. silent complications or vegetation size)
2. Asses treatment success on completion (e.g.valve morphology and cardiac function)
48
When doing a TTE at first, what are 4 possible outcomes and what is the next step?
1. prosthetic valve or intracardiac device (so TOE next)
2. poor quality TTE (so TOE next)
3. Positive ( so TOE next)
4. Negative (clinical suspicion of infective endocarditis assessed)
49
Once TTE is negative, what to do if clinical suspicion of infective endocarditis is
- high?
- low?
- if high then perform TOE (within 7-10 days)
| - if low then stop investigations
50
What are possible microbiology blood cultures which can arise in infective endocarditis patients? (4)
1. IE with +ve blood cultures
2. IE with -ve blood cultures ;prior to antibiotic prescription
3. IE with -ve blood cultures ;with fastidious organisms (ie require specific nutrients)
4. IE with -ve blood cultures; intracellular bacteria
51
What are IE +blood culture bacteria associated with 85% of IE? (3)
1. streptococci
2. enterococci
3. staphylococci
52
What subgroups of streptococci are associated with +blood cultures? (4)
1. oral viridans streptococci (s.sangitus, s.mitis, s.salivarius, s.mutans, germella, morbillorum)
2. S. milleri, S,anginosus group (S.anginosus, S intermedius, S. constellatus)
3. Abiotrophia and Granulicatella (recently reclassified nutritionally variant)
4. Group D streptococci (e.g. streptococcus bovis/ equinus complex associated withGI tract)
53
What subgroups of enterococci are associated with +ve blood cultures? (3)
1. E.faecalis
2. E. faecium
3. E. durans
54
What subgroups of staphylococcus are associated with +ve blood cultures? (2)
1. s. aureus (health care associated)
| 2. coagulase negative staph (CNS); S.epidermidis (health care associated)
55
If patient is an IV drug user or has a prosthetic valve, what bacterial infections would be more common?
Staph infections
56
If patient has an infection in their naive valve, what bacterial infection would be more common?
Strep infections
57
If blood culture is -ve prior to antibiotic treatment, why could this be? (3)
1. antibiotics given for unexplained fever
2. before blood cultures taken
3. diagnosis of IE not been considered
4. blood cultures may remain negative after the discontinuation of antibiotics (week +sometimes)
58
What are the causative organisms in a blood culture that is -ve prior to antibiotic treatment? (2)
1. oral streptococcus
| 2. CNS infection (s.pneumoniae, n. meningitidis)
59
What are the causative organisms in a blood culture that is -ve with fastidious organisms? (4)
1. nutritrionally variant streptococci
2. fastidious gram -ve bacilli (HACEK group)
3. Brucella
4. fungi
60
What are the HACEK group of fastidious gram negative bacilli?
H: h. aphrophilus, H. paraphrophilus, H.influenzae
A: actinobacillus, actinomycetemcomitans
C: cardiobacterium homitis
E: eikenella corrodens
K: kingella kingae, K. dentrificans
61
What are the causative organisms in a -ve blood culture with intracellular bacteria that makes up 5% of all IE? (3)
1. coxiella burnetti
2. bartonella
3. chlamydia
62
What microbiology testing can be done to identify intracellular bacteria? (4)
1. serological testing
2. PCR
3. cell culture
4. gene amplification
63
What are the major and minor criteria for Modified Duke Criteria when diagnosing infective endocarditis?
Major criteria:
- identifying organism
- providing evidence of infection anywhere within the heart
Minor criteria:
- focus on endocarditis complex of clinical findings
64
What are the MAJOR modified duke criteria for blood culture +ve for IE? (3)
Blood culture positive for IE:
1. typical organisms consistent with IE from 2 separate blood cultures (s.aureus, s.viridans, s. bovis, HACEK, comm.acq. enterococci)
2. organisms consistent with IE from persistently positive blood cultures
3. single positive blood culture for Coxiella Burnetti (or phase 1 IgG antibody titre.1:800)
65
What are MAJOR modified duke criteria for evidence of endocardial involvement? (2)
1. Positive Echo
- any endocardial surface, incl. normal myocardium
- intracardiac/device mass
- para-annular abscess
- new dehiscence of prosthetic valve
2. New valvular regurgitation/murmur
66
What are 5 components of MINOR modified Duke Criteria?
1. predispostion
2. fever
3. vascular phenomena
4. immunologic phenomena
5. microbiological evidence
67
What are possible IE predispositions as part of minor modified Duke Criteria? (2)
1. predisposing heart condition
| 2. IV drug use
68
What is possible IE fever as part of minor modified Duke Criteria?
temp >38 degrees
69
What are possible IE vascular phenomena as part of minor modified Duke Criteria? (6)
1. major arterial emboli
2. septic pulmonary infarcts
3. mycotic aneurysm
4. intracerebral haemorrhages
5. conjuctival haemorrhages
6. Janeway lesions
70
What are possible immunologic phenomena as part of minor modified Duke Criteria? (4)
1. glomerulonephritis
2. Osler's nodes
3. Roth spots
4. rheumatoid factor
71
What are possible microbiological evidence as part of minor modified Duke Criteria? (2)
1. +ve blood culture
| 2. serological evidence of active infection with organism consistent with IE
72
What is a DEFINITE diagnosis according to modified Duke Criteria? (3)
```
- 2 major
or
- 1 major and 3 minor
or
- 5 minor
```
73
What is a POSSIBLE diagnosis according to modified Duke Criteria? (2)
- 1 major
or
- 3 minor
74
What is the treatment for IE? (2) What form is it administered in?
1. antibiotics (different types)
in IV form
2. surgery +/-
75
When should antibiotic treatment be started?
as soon as all blood cultures taken
76
What will choice of antibiotic depend on? (3)
- received prior antibiotics
- native or prosthetic valve affected?
- knowledge of epidemiology e.g. specific culture negative pathogens and antibiotic resistance
77
What bacteria should be treated with aminoglycosides synergised with cell wall inhibitors (B lactams, glycopeptides)?
1. oral streptococci
2. enterococci
(good tolerance and slow growing, dormant microbes)
78
For how long should aminoglycoside synergised wtih cell wall inhibitors (B lactams, glycopeptides) treatment be given for?
prolonged therapy for 6 weeks + for oral streptococci and enterococci
79
What should native valve infections (including staph, strep, HACEK species and Bartonella species) be treated with? How long? (2)
1. IV gentamicin
2. IV amoxycillin
for 4 weeks
80
What should native valve infections + sepsis be treated with?
IV Vancomycin
81
Except from native valve infections, in what other circumstances should IV vancomycin be given? (3)
1. if penicillin allergic
2. in severe sepsis
3. if MRSA infection
82
What should prosthetic valve infections (including MSSA, MRSA, non HACEK G -ve pathogens) be treated with? How long? (1)
Rifampicin for 6 weeks
83
How should treatment for native valves infections (staph, strep, HACEK, Bartonella spp) be administered in terms of doses? (2)
1. IV Gentamicin 1mg/kg 12 hourly
| 2. IV Amoxycillin 2g 4 hourly
84
How should treatment for native valves and sepsis infections be administered in terms of doses? (1)
IV Vancomycin (as per protocol) + for penicillin allegic, MRSA and severe sepsis too
85
How should treatment for prosthetic valves infections (MSSA, MRSA, non HACKE G -ve pahtogens) in terms of doses? (1)
Rifampicin (300-600mg IV/ PO 12 hourly)
86
When should treatment be given?
only if blood culture +ve
87
What is antibiotic choice dictated by? (3)
1. microorganism isolated
2. sensitivities
3. resistance
88
What should treatment plan be in close liaison with? (2)
1. microbiologists
| 2. pharmacists
89
What are the toxic properties of Gentamicin? (2)
- nephrotoxic
| - ototoxic
90
What should serum gentamicin levels be ~4th dose at pre-dose and post-dose?
1. Through (pre-dose)
<= 1mg/L (ideally), if >2mg/L then withheld next dose
2. Peak (post dose)
1 hour after dosing, 3-5m/L
91
What tests should be done DAILY for IE treatment? (3)
1. full blood count
2. U+E
3. CRP (c reactive protein)
92
What test should be done every 1-2 days for IE treatment?
ECG
93
What test should be done weekly for IE treatment?
Echo
94
What patients are at risk of a fungi infection? (3)
1. prosthetic valve endocarditis
2. IV drug user
3. immunocompromised
95
What 2 species of fungi are common in IE patients?
1. Candida
| 2. Aspergillus
96
Do fungi infections have a high mortality in IE patients?
Yes, very high mortality
97
What treatment is given for fungal infection in IE patients? (2) What is the treatment duration?
- dual anti-fungals or valve replacement
| - long term treatment (often for life)
98
What are common complications for IE which are indications for surgery? (8)
1. heart failure (or pulmonary oedema)
2. fistula formation
3. leaflet/cusp perforation
4. uncontrolled infection
5. abscess formation and enlarging vegetation
6. atrioventricular heart block
7. embolism
8. prosthetic valve dysfunction
99
What is most frequent and severe complication for IE?
heart failure (with pulmonary oedema often)
100
What can indicate an uncontrolled infection as a complication in IE? (2)
1. persisting fever
| 2. +ve blood cultures >7-10 days
101
What are the causes for uncontrolled infection as a complication in IE? (7)
- inadequate antibiotic treatment
- resistant organisms
- infected lines
- locally uncontrolled infection
- embolic complications
- extracardiac site of infection
- adverse reaction to antibiotics
102
Where are abscess which lead to AV heart block as a complication to IE, common?
at the aortic root
103
What to do if peak levels (post dose) of Gentamicin are correct/adequate?
- don't need to do repeat unless dose altered
| - re-check after 4th dose of new regime
104
What to do if through levels (pre dose) of Gentamicin are correct/adequate?
- repeat 3 x week
- close monitoring U+Es
- if dose change, recheck after 4th dose of new regime
105
What dose of Vancomycin should be given (for native valve +sepsis infection)?
15-20mg/L, as per protocol on intranet
106
In what type of endocarditis would high levels of IV Vancomycin be appropriate?
in enterococcal endocarditis
107
What is the toxic property of Vancomycin?
it's nephrotoxic
108
How to prevent embolism as a complication for IE? (6)
1. check size/mobility of vegetation (abnormal growth)
2. increase size of antibiotic
3. check staph, strep bovis and candida infections
4. check if previous embolism in the past
5. isolated vegetation >15mm and embolism +vegetation >10mm
6. multivalvular IE
109
What is the most severe form of IE?
prosthetic valve endocarditis (1-6% of valve prosthesis patients)
110
How many cases of all IE are made up of prosthetic valve endocarditis?
10-30%
111
What is prosthetic valve endocarditis (worse prognosis IE) associated with? (4)
1. difficulties in diagnosis
2. difficulties with optimal therapeutic strategy
3. poor prognosis
4. removal of prosthetic material
112
What is medical therapy alone on prosthetic valves (intracardiac devices) associated with? (2)
- high mortality
| - risk of recurrence
113
In what cases is prosthetic valve removal recommended? (2)
1. proven cases
| 2. in suspected cases also
114
How should IV antibiotics be given prior to removal of prosthetic valve?
for as long as possible to sterilise device/prosthesis
115
What group of patients should only be limited to prophylaxis treatment?
only HIGH risk patients
- transient bacteraemia
- daily activities (poor dental hygiene)
but little evidence on IE prophylaxis.
116
What cardiac conditions are at highest risk of IE?
1. acquired valvular disease (stenosis or regurgitation)
2. valve replacement
3. structural congenital heart disease (surgically corrected or palliated,excluding: isolated ASD, fully repaired CSD and PTA, closure endotheliased devices)
4. hypertrophic cardiomyopathy
5. previous IE
117
What advice should be given to patients at risk of IE about prevention? (5)
1. benefits and risks of antibiotic prophylaxis
2. explain why antibiotic prophylaxis is no longer routinely used
3. importance of good oral health
4. symptoms of IE and when to seek medical advice
5. risk of undergoing invasive procedures; medical and non-medical (tattooing or piercings)
118
When to offer prophylactic treatment for IE? (5)
1. offer antibiotic that covers organisms that cause IE
2. if person at risk of IE
3. if patient receiving antimicrobial therapy
4. if patient is due to undergo a GI or GU precedure
5. at a site where there is suspected infection
119
When NOT to offer prophylactic treatment for IE? (2)
1. for dental procedures
2. for non dental procedures; upper/lower GI, genitourinary such as urological, gynaecological, obstetric, childbirth procedures), upper/lower resp. tract e.g. ENT, throat procedures or bronchoscopy
120
Health care associated IE make up what portion of all IE?
30%
121
Is routine prophylaxis recommended for patients in health care setting?
No
122
What aseptic measures need to be reviewed to prevent health care associated IE? (2)
1. insertion
2. manipulation
of venous catheters and invasive procedures
123
What patient characteristics can affect patient prognosis (outcome) of their IE? (4)
- older age
- prosthetic valve IE
- insulin dependent diabetes mellitus
- comorbidity (e.g. previous CV, renal, resp. disease)
124
Presence of what complications can affect patient prognosis with IE? (5)
1. heart failure
2. renal failure
3. stroke
4. septic shock
5. periannular complications
125
What microorganisms are closely related to patient prognosis with IE? (3)
1. s. aureus
2. fungi
3. gram negative bacilli
126
What echo findings can affect patient prognosis in IE? (6)
1. periannular complication
2. pulmonary hypertension
3. severe l. sided valve regurgitation
4. large vegetations
5. severe prosthetic dysfunction
6. premature mitral valve closure and other signs of elevated diastolic pressures
