Andersons pediatric cardiology 1369
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FIG.52.1 Leftventricularmyxomainanadult.Itiseasytoseehowparts
ofthetumorcanfragmentandembolizetothesystemiccirculation.
FIG.52.2 Sectionacrossanintramuralcoronaryarterythatiscompletely
occludedbyathrombusdetachedfromthesurfaceofanintracardiac
myxoma.
Ingeneral,left-sidedtumorsembolizetothesystemiccirculation.Hencethey
mayaffectalmostanyorgan,eventheheartitself.18Suddenocclusionofa
peripheralarteryshouldalwaysalerttothepossibilityofembolizationfroma
primaryintracardiactumorandshouldalerttothepossibilityofcerebral
embolism.16Moreover,multiplesystemicembolizationmaymimicsystemic
vasculitisorinfectiveendocarditis,particularlywhenproducingsystemic
manifestations.
Primarytumorsintherightheartchambersmaycausepulmonaryembolism.19
Thismaybeindistinguishablefrompulmonaryembolismsecondarytovenous
thromboembolism.Perfusiondefectsinthelungduetoembolizationfroma
tumordonotusuallyresolvewithinafewweeks,astheydowithvenous
embolization.Embolizationfromatumormayalsobesuggestedbycomplete
absenceofflowtoonelunginthepresenceofanormalperfusionscanonthe
oppositelung.Thisismostunusualinpatientswithrecurrentpulmonaryvenous
thromboembolism.
CardiacManifestations
Thecardiaceventsarelargelydependentonthelocationandextentofthetumor
withintheheart.Tumorsthatarelocalizedwithinthemyocardiummaybe
asymptomaticanddiscoveredincidentallyonimagingstudiesoratautopsy.
Detectionofacardiacmassonroutineobstetricsonographicscanisoftenthe
initialfindinginfetuses.1
Arrhythmias
Disturbancesofcardiacrhythmcanbethefirstmanifestationofaprimary
cardiactumor.20Shouldthetumorbelocatedintheregionoftheatrioventricular
nodeorconductionaxis,evensmalltumorsmayproducedisturbancesof
atrioventricularconduction.Completeatrioventricularblockandsuddendeath
areseenastheextremeclinicalmanifestation,especiallyforrhabdomyomas.1
Moreover,theintramurallocationofprimarytumorsmayunderlieawidevariety
ofdisturbancesofrhythm,includingatrialfibrillationorflutter,paroxysmal
atrialtachycardia,atrioventricularjunctionalrhythm,partialorcomplete
atrioventricularblock,supraventriculartachycardia,atrialandventricular
prematurebeats,ventriculartachycardia,andventricularfibrillation.20–23
CardiacFailureandPericardialEffusion
Infiltrativetumorsofthemyocardiumcancausehemodynamiccompromise.
Thistendstooccurlateintheclinicalcoursewhenthereissubstantial
involvementofthemyocardiumorpericardium(Fig.52.3),producingsymptoms
ofcardiacfailureconsequenttosystolicand/ordiastolicdysfunction.1Insome
instances,theclinicalpresentationmaymimicthatofdilated,restrictive,or
hypertrophiccardiomyopathy.24,25Pericardialexudates,eventuallywithcardiac
tamponade,maybethefirstsymptomoftheepicardiallocationofatumor.26,27
Thisismainlyseenwithteratomas,vasculartumors,malignanttumors,and
secondarylesions.
