Andersons pediatric cardiology 1484

Classification
TheclassificationofIEisoutlinedinTable56.1.Currently,onlyapproximately
10%ofpediatricIEisanativevalveendocarditis(NVE).
Table56.1
ClassificationofInfectiveEndocarditis(IE)
ACCORDINGTOLOCALIZATIONANDPRESENCE/ABSENCEOFINTRACARDIACMATERIAL
Left-sidednativevalveIE
Left-sidedprostheticvalve
IE
Early
<1yearafterreplacement
Late
>1yearafterreplacement
Right-sidedIEa
Cardiacdevice–relatedIEb
ACCORDINGTOMODEOFACQUISITION
Healthcare–associatedIE
Nosocomial
Hospitalized>48hpriortoonsetofsymptoms
Nonnosocomial
Hospitalized<48hpriortoonsetofsymptomsif:
■Home-basednursingorintravenousprocedures<30daysbeforeonset
■Hospitalizedinacutecarefacility<90daysbeforeonset
■Residentinnursinghomeorlong-term-carefacility
Community-acquiredIE
Onsetofsymptomsoutofhospitalor<48hafterhospitalizationifcriteriaforhealth
care–associatednotfulfilled
Intravenousdrugabuse–
IEinactiveinjectiondruguserwithoutalternativesourceofinfection
associatedIE
ACTIVEIE

IEwithpersistentfeverorpositivebloodculture
Activeinflammatorymorphologyatsurgery
Stillunderantibiotictherapy
HistopathologicevidenceofactiveIE
RECURRENCEOFIE
Relapse
Repeatepisodewithsamemicroorganism<6monthsaftertheinitialepisode
Reinfection
Repeatepisodewithsamemicroorganism>6monthsaftertheinitialepisode
Infectionwithdifferentmicroorganism
aIncludingtricuspidvalvesupporting/additionaltissueatpartiallyclosedorresidualventricular

septaldefect,transcatheterandsurgicalpulmonaryvalvereplacement(prostheticvalve,
homograft,valvedconduit).
bCardiacimplantableelectronicdevice(CIED)likepermanentpacemakers(PPMs)and

implantablecardioverter-defibrillator(ICD);Transcatheterintroducedvalvesandclosuredevices
(ASD/VSD/PDAclosing)beforeendothelization;Long-termcatheterrelated(Portacath,Hickman
lineandPeripherallyinsertedcentralline),othercentrallinesreachingtheheart.
ModifiedfromESCguidelines2009.


ClinicalManifestations
Theheterogeneousclinicalmanifestationswithregardtosignsandcourse,as
wellasthepossiblemultiorganinvolvement,explainwhyIEstillpresentsa
diagnosticchallenge.Thesignsarerelatedto:
1.Infection:fever(>90%),positivemarkersofinflammation(elevated
erythrocytesedimentationrate/C-reactiveprotein,anemianormocyticor
microcyticwithlowserumironandnormalorhighferritin,leukocytosis
withneutrophilia),positivebloodculture(BC)(>70%).

2.Destruction(>90%):newcardiacmurmur,heartfailure(30%to60%),
conductionabnormality.Becausechildrenwithcongenitalheartdefects
oftenhaveaprecedingmurmur,anewmurmurisdifficultto
differentiate.Heartfailureiscausedbyacutesevereaorticormitral
insufficiencyorintracardiacfistulaeandonlyrarelybyvalve
obstruction.Conductionabnormality(rightandleftbundlebranchblock,
aswellascompleteheartblock)canbeobservedandisduetospreadof
infectiontotheconductionsystem.
3.Embolism(20%to50%):systemic(brain,spleen,kidney,peripheral)or
pulmonary.Pulmonarythromboembolism(PTE)isalmostuniversally
presentinright-sidedendocarditis.Neurologiccomplications(local
braininvolvementintheareaoftheembolization,ischemicstroke,
mycoticaneurysm,subarachnoidhemorrhagesecondarytomycotic
aneurysmrupture)mightbemoreoftenseenthanthecurrentlyreported
30%.Thesecontinueoccurringusuallyuptothefirst2weeksafterstart
ofantibiotictreatment.
4.Immunologicphenomena(positiveantinuclearantibodyand
rheumatoidfactor,lowC3/C4).Hematuriamayberelatedbothto
immunologiccomplexdepositionorsmallrenalemboli.
Theclassicalsubacutepresentationoverweeksandsometimesmonthsis
characteristicforviridansgroupstreptococci(VGS)andislessoftenseen.Acute
presentationisnowprevailingasIEcausedbystaphylococci,particularlyS.
aureushasbecomemorefrequent.Wedonotusethetypeofpresentationfor
classificationpurposes.


ClinicalmanifestationsleadingtosuspicionofIEaresummarizedinBox
56.2.

Box56.2

WhentoSuspectInfectiveEndocarditis?
IEmustbesuspectedinthefollowingsituations:
1.Newregurgitantheartmurmur.
2.Emboliceventsofunknownorigin.
3.Sepsisofunknownorigin(especiallyifassociatedwithIEcausative
organism)
4.Fever(>90%ofpatients).IEmustbesuspectediffeverisassociatedwith:
a.Intracardiacprostheticmaterial(e.g.,prostheticvalve,pacemaker,
implantablecardioverterdefibrillator,surgicalbaffle/conduit)
b.PrevioushistoryofIE.
c.Previousvalvarorcongenitalheartdisease.
d.OtherpredispositionforIE(e.g.,immunocompromised,
intravenousdrugusers).
e.Predispositionandrecentinterventionwithassociatedbacteremia.
f.Newcongestiveheartfailure.
g.Newconductiondisturbance.
h.PositivebloodculturewithtypicalIEcausativeorganismor
positiveserologyforQ-feverorBartonella(microbiologicfindings
mayprecedecardiacmanifestations).
i.Vascularorimmunologicphenomena:embolicevent,Rothspots,
splinterhemorrhages,Janewaylesions,Oslernodes.
j.Focalornonspecificneurologicsymptomsandsigns.
k.Evidenceofpulmonaryembolism/infiltration(right-sidedIE).
l.Peripheralabscesses(renal,splenic,cerebral,vertebral)of
unknowncause.
IE,Infectiveendocarditis.