3. Introduction
Is an infection of the
endocardium and/or heart valves that
involves thrombus formation
(vegetation), which may damage the
endocardial tissue and/or valves.
Bacteria are the predominant
microbial pathogens
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4. Nonbacterial endocarditis can be
caused by viruses, fungi, and other
microbiologic agents.
It is a significant cause of morbidity
and mortality in children and
adolescents despite advances in the
management and prophylaxis of the
disease with antimicrobial agents.
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5. Native or prosthetic heart valves are
the most frequently involved sites.
Endocarditis also can involve septal
defects, the mural endocardium, or
intravascular foreign devices such as
intracardiac patches, surgically
constructed shunts, and intravenous
catheters.
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6. Infective endarteritis is a similar
clinical illness involving arteries,
including the ductus arteriosus, the
great vessels, aneurysms, or
arteriovenous shunts.
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7. EPIDEMIOLOGY
The prevalence of definite IE was
approximately 12%, and definite or
possible IE was 20%.
About 35-50% of children with IE have
CHD.
The risk of IE is increased in patients
with complex cyanotic heart disease,
especially in those who undergo
surgical procedures
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8. The cumulative incidence of IE over
25 years following surgery was
determined for the following CHD
defects.
Valvular aortic stenosis — 13.3%
Coarctation of the aorta — 3.5%
Primum atrial septal defect — 2.8%
Ventricular septal defect (VSD) — 2.7%
Tetralogy of Fallot (TOF) — 1.7%
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9. ETIOLOGIES
Gram-positive cocci account for about
90% of recoverable bacteria( Adult
studies)
Viridans-type streptococci (α-hemolytic
streptococci) and S.aureus remain the
leading causative agents.
Staphylococcal endocarditis is more
common in patients with no underlying
heart disease.
viridans group streptococcal infection is
more common after dental procedures.
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10. Group D enterococci are seen more
often after lower bowel or
genitourinary manipulation.
P.aeruginosa or S.marcescens is seen
more frequently in intravenous drug
users.
Fungal endocarditis – one of the most
feared forms (complications, like
embolization are common)
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11. Fungal organisms are encountered
after open heart surgery.
Coagulase-negative staphylococci are
common in the presence of an
indwelling central venous catheter.
Gram-negative organisms cause
<10% of the endocarditis in children.
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12. Approximately 5% -10% of patients
with endocarditis have negative blood
cultures.
The most common cause of culture-
negative IE is current or recent
antibiotic therapy or infection caused
by a fastidious organism that grows
poorly in vitro.
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13. Pathogenesis
Turbulent flow traumatizes the
vascular endothelium, creating a
substrate for deposition of fibrin and
platelets, leading to the formation of a
nonbacterial thrombotic embolus
(NBTE).
Biofilms form on the surface of
implanted mechanical devices such as
valves, catheters, or pacemaker wires
that also serve as the adhesive
substrate for infection.
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14. The development of transient
bacteremia then colonizes this NBTE
or biofilm, leading to proliferation of
bacteria within the lesion.
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15. Occurrence of transient bacteremia
Adherence of bacteria to the NBTE
Proliferation of bacteria with in the
vegetation
Large fibrin deposit encase the bacteria
inside
Prevent phagocytosis and anti-microbial
penetration
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16. Virtually all vegetations occur in areas
where there is a pressure gradient with
resulting turbulence of blood flow.
The sites of high-velocity jets where
most IE vegetations occur are on the
atrial side of the atrioventricular valves
and the ventricular side of the semilunar
valves.
In ≈30% of patients with infective
endocarditis, a predisposing factor is
presumably recognized.
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17. Relative risk of IE for underlying
cardiac lesions & conditions
High risk:
prosthetic valves
Previous episode of endocarditis
Complex cyanotic congenital heart
diseases (e.g. single ventricle states,
TGA, TOF)
Surgically corrected systemic artery to
pulmonary artery shunts
Injection drug use
Indwelling central venous catheters
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29. DIAGNOSIS
Blood culture
Three to 5 separate blood collections
should be obtained.
The timing of collections is not
important because bacteremia can be
expected to be relatively constant.
In 90% of cases of endocarditis, the
causative agent is recovered from the
first 2 blood cultures
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30. Usually 20 to 30 mL of blood is collected
from an adult patient, but this is not
possible in a small child.
Thus 1 to 3 mL in infants and young
children and 5 to 7 mL in older children
are optimal.
Usually, three blood cultures are
obtained by separate venipunctures on
the first day, and if there is no growth by
the second day of incubation, two more
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31. Antimicrobial pretreatment of the patient
reduces the yield of blood cultures to 50-
60%
Echocardiography
◦ evidence of valve vegetations,
◦ prosthetic valve dysfunction or leak,
◦ myocardial abscess,
◦ new-onset valve insufficiency
◦ predicting embolic complications( fungating
mass >1cm in size)
◦ sensitivities in children reported to be >80%
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32. Other laboratory findings
Elevated erythrocyte sedimentation rate; may be low
with heart or renal failure
Elevated C-reactive protein
Anemia
Leukocytosis
Immune complexes
Hypergammaglobulinemia
Hypocomplementemia
Rheumatoid factor
Hematuria
Renal failure: azotemia, high creatinine
(glomerulonephritis)
Chest radiograph: bilateral infiltrates, nodules, pleural
effusions
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33. Duke crteria
Major criteria
1) positive blood cultures (2 separate
cultures for a usual pathogen, 1 or more
for less-typical pathogens), and
2) evidence of endocarditis on
echocardiography
-intracardiac mass on a valve or other site
-regurgitant flow near a prosthesis
-abscess
-partial dehiscence of prosthetic valves, or
- new valve regurgitant flow
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34. Minor criteria
Predisposing conditions,
fever,
Embolic-vascular signs,
Emmune complex phenomena
(glomerulonephritis, arthritis, rheumatoid
factor, Osler nodes, Roth spots),
A single, positive blood culture or
Serologic evidence of infection, and
Echocardiographic signs not meeting the
major criteria.
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35. clubbing,
splenomegaly,
splinter hemorrhages,
petechiae
a high erythrocyte sedimentation rate
a high C-reactive protein level
the presence of central nonfeeding
lines, peripheral lines,
microscopic hematuria
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36. Definite infective endocarditis (IE):
Pathologic criteria:
◦ Micro-organisms demonstrated by culture or
histologic examination of a vegetation, a
vegetation that has embolized, or an intracardiac
abscess specimen; or
◦ Pathological lesions; vegetation or intracardiac
abscess confirmed by histologic examination
showing active endocarditis
Clinical criteria :
◦ 2 major criteria; or
◦ 1 major criterion and 3 minor criteria; or
◦ 5 minor criteria
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37. Possible IE:
◦ 1 major criterion and 1 minor criterion; or
3 minor criteria
Rejected IE:
◦ Firm alternative diagnosis explaining
evidence of IE; or
◦ Resolution of IE syndrome with antibiotic
therapy for 4 days; or
◦ No pathologic evidence of IE at surgery or
autopsy, with antibiotic therapy for 4 days; or
◦ Does not meet criteria for possible IE as
above
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41. treatment
Antimicrobial
General principles
◦ Prolonged periods of treatment(4 to 6
weeks)
◦ Bacteriocidal rather than bacteriostatic
◦ Parentral antibiotic
◦ High dose
◦ Combination of antibiotic which have
synergistic effect
◦ Managed in hospital initialy
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42. Antibiotic therapy should be instituted
immediately once a definitive
diagnosis is made.
outpatient therapy can be undertaken
if the patient is afebrile, has negative
blood cultures, and is at negligible
risk for complications.
Empiric therapy should cover
staphylococci, streptococci, and
enterococci.
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43. Most patients with IE become afebrile
5-6 days after treatment is begun with
an appropriate antibiotic.
Patients with S. aureus endocarditis
may respond somewhat more slowly,
remaining febrile for 5-7 days after the
institution of therapy
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44. The initial microbiologic response to
therapy should be assessed by
obtaining repeat blood cultures 48 -72
hours after antibiotics are begun.
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45. Surgical management
INDICATIONS
◦ Severe aortic, mitral or prosthetic valve
involvement with intractable heart failure.
◦ Mycotic aneurysm
◦ Rupture of an aortic sinus
◦ Intraseptal abscess causing complete
heart block
◦ Dehiscence of an intracardiac patch
◦ Fungal endocarditis
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46. ◦ Failure to sterilize the blood despite
adequate antibiotic levels in 7-10 days
◦ Increasing size of vegetations while
receiving therapy.
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48. CONGENITAL HEART DISEASE
(CHD)
Unrepaired cyanotic CHD
Completely repaired CHD with
prosthetic material or device during
the 1st 6 mo after the procedure
Repaired CHD with residual defects
Cardiac transplantation recipients who
develop cardiac valvulopathy.
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49. reference
Nelson 20th edition
Moss and Adams cardiology 7th edition
Uptodate 20.2
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