2. DEFINITION
Infective Endocarditis (IE): an infection of the
heart’s endocardial surface and or heart valves
that involves thrombi formation which may
damage endocardial tissues or valves
Classified based on temporal evolution of
disease, the site of infection, the cause of
infection, or the predisposing risk factor.
2
3. CLASSIFICATION BASED ON TEMPORAL
EVOLUTION OF THE DISEASE
Acute
Affects normal heart valves
Hectically febrile illness that rapidly damages cardiac
structures and hematogenously seed extracardiac sites
If not treated, usually fatal within 6 weeks
Commonly due to S.aureus
3
4. CONT’D….
Subacute
Often affects damaged heart valves
Indolent nature,characterized by prolonged course of LGF,
and nonspecific compliants :fatigue, arthralgia, wt loss,
diaphoresis
Rarely metastasize
There is risk of immunologic sequelae:GN
If not treated, usually fatal by one year
Due to less virulent organisms: V.streptococci,CONS
4
5. CLASSIFICATION (BASED ON PREDISPOSING RISK FACTORS)
1. Native valve endocarditis
Community acquired
Health care-associated (nosocomial) endocarditis: defined as a
diagnosis of IE made more than 72 hours after admission in
patients with no evidence of IE on admission, or IE developing
within 60 days of a prior admission when there was a risk factor
for bacteremia or any risk factor for IE during the hospitalization
2. Prosthetic valve endocarditis
3. Endocarditis in IVD abusers
5
6. EPIDEMIOLOGY
Incidence difficult to ascertain and varies according to
location but it is relatively uncommon disease
Much more common in males than in females(M:F
ratiovaries from 2:1-9:1)
May occur in persons of any age and increasingly
common in elderly
Mortality ranges from 20-30% with Rx , up to100% fatal
with out Rx.
6
7. RISK FACTORS
Intravenous drug abuse
Artificial heart valves and pacemakers
Acquired heart defects
Rheumatic heart disease
Calcific aortic stenosis
Congenital heart defects(VSD,PDA,COA,TOF,BAV)
Intravascular catheters
Prior episode of infective endocarditis: recurrence is
9%
NB. The higher gradient flow lesions( high pressure
to low pressure) are highly risk for IE. 7
8. ETIOLOGY( MICROBIOLOGY)
Common bacteria
Viridans group streptococci (S. mutans, S.
sanguis, S. mitis)
Staphylococcus aureus
Group D streptococcus (enterococcus) (S. bovis,
S. faecalis)
Not so common bacteria
Pseudomonas
H.influenze
HACEK (Haemophilus species, Aggregatibacter
aphrophilus, Actinomycetemcomitans,
Cardiobacterium species,Eikenella species, and
Kingella species)
Fungi
8
9. PATHOPHYSIOLOGY1. Turbulent blood flow disrupts the endocardium making it
“sticky”
2. At the site of the damage, fibrin, platelet and occasionally
RBCs are deposited and form- nonbacterial thrombotic
endocarditis (NBTE)
3. Transient Bacteremia or fungemia delivers the organisms
to the endocardial surface
4. Adherence of the organisms to the injured endocardial
surface and thrombus
5. Eventual invasion of the valvular leaflets – further
deposition of platelets resulting in vegetation's
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10. SYMPTOMS
Acute
High grade fever and
chills
SOB
Arthralgia/ myalgia
Abdominal pain
Pleuritic chest pain
Back pain
Subacute
Low grade fever
Anorexia
Weight loss
Fatigue
Arthralgia/ myalgia
Abdominal pain
N/V
The onset of symptoms is usually ~2 weeks or less
from the initiating bacteremia
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11. SIGNS
Fever
Heart murmur( new or changing murmur)
Nonspecific signs – petechiae, subungal or “splinter”
hemorrhages, clubbing, splenomegaly, neurologic
changes
More specific signs - Osler’s Nodes, Janeway lesions,
and Roth Spots
11
13. PERIPHERAL SIGN OF IE
Janeway lesions: are macular, blanching, nonpainful, erythematous
lesions on the palms and soles
Osler's nodes: are painful, papulopustular to violaceous nodular
lesions found in the pulp of fingers and toes and are seen more
often in sub acute than acute cases of IE
Roth spots are exudative, edematous hemorrhagic lesions of the
retina
Petechiae
Splinter hemorrhage: are nonblanching, linear reddish-brown
lesions found under the nail bed
13
14. PETECHIAE
Photo credit, Josh Fierer, M.D.
medicine.ucsd.edu/clinicalimg/ Eye-Petechiae.html
Harden Library for the Health Sciences
www.lib.uiowa.edu/ hardin/
md/cdc/3184.html
1.Nonspecific
2.Often located on extremities
or mucous membranes
dermatology.about.com/.../
blpetechiaephoto.htm
14
15. SPLINTER HEMORRHAGES
1. Nonspecific
2. Nonblanching
3. Linear reddish-brown lesions found under the nail bed
4. Usually do NOT extend the entire length of the nail
15
18. OSLER’S NODES
1. More specific
2. Painful and erythematous nodules
3. Located on pulp of fingers and toes
4. More common in subacute IE 18
19. COMPLICATIONS
Four etiologies
Embolic eg stroke
Local spread of infection
Metastatic spread of infection
Formation of immune complexes –
glomerulonephritis and arthritis
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20. EMBOLIC COMPLICATIONS
Occur in up to 40% of patients with IE
Predictors of embolization
Size of vegetation(>or= to 10mm)
Left-sided vegetations
Fungal pathogens, S. aureus, and Strep. Bovis
Incidence decreases significantly after initiation of
effective antibiotics
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21. EMBOLIC COMPLICATIONS
Stroke
Myocardial Infarction
Fragments of valvular vegetation or vegetation-induced
stenosis of coronary ostia
Ischemic limbs
Hypoxia from pulmonary emboli
Abdominal pain (splenic or renal infarction)
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22. LOCAL SPREAD OF INFECTION
Heart failure
Due to extensive valvular damage or acute MI
Commonest Couse of death
Paravalvular abscess (30-40%)
Most common in aortic valve, IVDA, and S. aureus
May extend into adjacent conduction tissue causing
arrythmias
Higher rates of embolization and mortality
Pericarditis
Fistulous intracardiac connections 22
24. INVESTIGATION
Blood Cultures
3- 5 separate blood collection should be obtained after careful
preparation for phlebotomy site depending on severity of illness
In most patients 3 BC are obtained with in the 1st 24 hrs
and additional 2 BC in the next 24 hrs if no growth
In critically ill patients 3 venipuncture site for blood culture
should be obtained as fast as possible
Obtain 10-20mL in adults and 0.5-5mL in children2
Positive Result:
Typical organisms present in at least 2 separate samples
Persistently positive blood culture (atypical organisms)
Two positive blood cultures obtained at least 12 hours apart
Three or more positive blood cultures in which the first and
last samples were collected at least one hour apart 24
26. IMAGING
Chest x-ray
Look for multiple focal infiltrates and calcification of heart
valves
EKG
Rarely diagnostic
Look for evidence of ischemia, conduction delay, and
arrhythmias
Echocardiography
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27. INDICATIONS FOR
ECHOCARDIOGRAPHY
Transthoracic echocardiography (TTE)
First line if suspected IE
Native valves
Transesophageal echocardiography (TEE)
Prosthetic valves
Intracardiac complications
Inadequate TTE
Fungal or S. aureus or bacteremia
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28. DIAGNOSIS
Modified Duke Criteria
Definite IE
Clinical criteria
Two major criteria, or
One major and three minor criteria, or
Five minor criteria
Pathologic criteria
Microorganism: (via culture or histology) in a valvular
vegetation, embolized vegetation, or intracardiac
abscess
Pathological lesions: vegetation or intracardiac
abscess present, confirmed by histology showing
active endocarditis 28
29. CON’D
Possible IE
One major criterion and one minor criterion
or three minor criteria
Rejected IE
Firm alternative diagnosis for manifestations
of endocarditis, or
Sustained resolution of manifestations of
endocarditis, with antibiotic therapy for 4
days or less, or
No pathological evidence of infective
endocarditis at surgery or autopsy, after
antibiotic therapy for 4 days or less 29
30. CON’D
Major Criteria
Positive blood culture
Typical microorganism for infective endocarditis from two
separate blood cultures
Persistently positive blood culture, defined as recovery of
a microorganism consistent with infective endocarditis
from:
Blood cultures (≥2) drawn more than 12 hr apart, or
All of three or a majority of four or more separate blood
cultures, with first and last drawn at least 1 hr apart
Single positive blood culture for Coxiella burnetii or
antiphase I IgG antibody titer >1:800
30
31. CON’D
Evidence of endocardial involvement
Positive echocardiogram
Oscillating intracardiac mass, on valve or supporting structures, or in
the path of regurgitant jets, or on implanted material, in the absence
of an alternative anatomical explanation, or
Abscess, or
New partial dehiscence of prosthetic valve, or
New valvular regurgitation (increase or change in
preexisting murmur not sufficient)
31
32. CON’D
Minor Criteria
Predisposition: predisposing heart condition or
intravenous drug use
Fever ≥38.0°C (100.4°F)
Vascular phenomena: major arterial emboli, septic
pulmonary infarcts, mycotic aneurysm, intracranial
hemorrhage, conjunctival hemorrhages, Janeway
lesions
Immunological phenomena: glomerulonephritis,
Osler nodes, Roth spots, rheumatoid factor
Microbiological evidence: positive blood culture but
not meeting major criterion as noted previously[*] or
serologic evidence of active infection with organism
consistent with infective endocarditis
32
33. CON’D
The following minor criteria are added to those
already listed:
splenomegaly
splinter hemorrhages, and petechiae
a high erythrocyte sedimentation rate
a high C-reactive protein level
the presence of central non feeding lines
peripheral lines
microscopic hematuria
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34. TREATMENT
Parenteral antibiotics
High serum concentrations to penetrate vegetations
Prolonged treatment to kill dormant bacteria clustered in
vegetations
Surgery
Intracardiac complications
intractable heart failure
failure to sterilize the blood despite adequate antibiotic
levels
increasing size of vegetations while receiving therapy
Surveillance blood cultures
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35. Acute endocarditis or prosthetic valvae endocarditis
vancomycin 30mg/kg/day(ceftriaxone 2gm/day) plus gentamycin
3mg/kg/day once daily or in 2-3 divided doses immedietly after blood
culture.
Subacute endocarditis –if patient hemodynamically stable wait
for 2- 3 days till blood culture result.
Culture positive treat based on the isolated organisms
Culture is negative endocarditis
SBE-ceftriaxone 2gm /day+gentamycin 3gm/kg for the 1st 2wks and
continue with ceftriaxone only for the remaining weeks of therapy
Acute endocarditis –continue vancomycin +gentamycin for 2wks and
then vancomycin for the remaining wks of therapy
patients with proven or suspected enterococcal endocarditis should
receive combination of vancomycin and gentamycin for the whole
duration of therapy.
Duration of therapy- 4wks for most patients 35
36. PREVENTION
Antimicrobial prophylaxis before various
procedures and other forms of dental
manipulation may reduce the incidence of
infective endocarditis in susceptible patients
36