Andersons pediatric cardiology 1371
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Investigations
LaboratoryStudies
Thesearenonspecific.Abnormalfindingsmayincludeelevatederythrocyte
sedimentationrate,C-reactiveprotein,hypergammaglobulinemia,
thrombocytosis,thrombocytopenia,polycythemia,leukocytosis,andanemia.
Electrocardiography
Theelectrocardiogrammayalsobenonspecific.Alltypesofdisturbancesof
rhythmandconduction,andabnormalitiesofvoltageandtheST-Tsegments,
maybeseen.1,20Theelectrocardiogrammayalsodisplaythetypicalpatternof
atrialdilationorventricularhypertrophy.1,15Incidentallow-voltagecomplexes
mayberegistered,indicatingpossiblepericardialinvolvement.Occasionally,it
ispossibletofindthepatternofventricularpreexcitation.1,5Thisisparticularly
thecasewhentheaccessorymuscularatrioventricularpathwaysarecomposedof
theintracardiactumor.32,33
ChestRadiography
Cardiactumorsmayalterthecontoursoftheheart,butthechangesin
themselvesaremostoftennonspecific.Thecardiaccontourmaybenormalor
maydisplayenlargementofeithertheentireheartoranyparticularchamber.34–36
Grossandbizarredistortionsofthecardiaccontouroccasionallyoccurthatare
thensuggestiveofatumor.Theoverallpicturemaybefurthercomplicatedby
thepresenceofpericardialfluid.Radiographicsignsofpulmonaryvenous
obstructionwithleftatrialenlargementmaybeobservedinpatientswith
obstructiveleft-sidedtumors.Calcificationofaprimarytumormayoccasionally
besointensethatitcanbenotedonthechestradiograph(Fig.52.5).34,35
FIG.52.5 Extensivelycalcifiedrightatrialmyxomafromanadultheart.
Inset,Postmortemradiograph.Calcificationofthisextentwasalsoseenon
chestradiographsduringlife.
Echocardiography
Echocardiographyisuniversallyestablishedasthefirst-lineandmaindiagnostic
modalityfortumorassessment.Transthoracicechocardiographyishighly
portableandubiquitous,withveryhighspatialandtemporalresolution.Itallows
foraccuratedeterminationofthesize,shape,texture,location,attachment,
mobility,andhemodynamicconsequencesofthetumor.Echocardiographygives
informationastowhetherthetumorisencapsulatedandwhetheritissolidor
cystic.37Texturemaybeinferredbythegrayscaleappearance,although
interpretationremainssubjective.38Colorflowmappinghasbeenappliedto
distinguishtumormassfromendocardium.39,40Three-dimensional
echocardiographymayallowforimprovedvisualizationofmorphologicand
spatialcharacteristicsofcardiacandparacardiactumors,establishingtheir
relationshipswithadjacentstructures,andincertaincasesmaybesuperiorto
transthoracicechocardiographyintheevaluationofthesizeofintracardiac
masses(Fig.52.6).41–45
FIG.52.6 Dynamicthree-dimensionalechocardiographyshowinga
myxomaina12-year-oldboy,originatingintheleftatriumandattachedto
theatrialseptumintheregionoftheovalfossa.Thetumorisprotruding
intotheatrioventricularorificeduringventriculardiastole.(CourtesyDr.Jan
Marek,GreatOrmondStreetHospital,London,UnitedKingdom.)
Transesophagealechocardiographycanbeausefuladjuncttotransthoracic
imaging,notablyinpatientswithsuboptimaltransthoracicwindows.Insuch
patientsitisideallysuitedfortheexaminationofposteriorstructuressuchasthe
atriums,interatrialseptum,cavalveins,andatrioventricularvalves.46Another
importantapplicationisthedifferentiationoftruepathologyfromnormal,or
variantsofnormal,anatomysuchastheterminalcrestoftherightatrium.In
addition,transesophagealtwo-andthree-dimensionalimagingcanbeused
intraoperativelytoassistwithsurgicalexcisionofcardiactumorsortoguide
transvenousbiopsy.3,47
Thediagnosticsensitivityoftransthoracicandtransesophagealapproacheshas
beenreportedtobe93.3%and96.8%,respectively.48Thesensitivityisgreatest
forendocardiallesions,wherethecontrastbetweentumorandanecholucent
cavityismostapparent,permittingcharacterizationofthesizeandmobilityof
themasses.Incontrast,echocardiographicassessmentofthepericardialtumors
maybemorelimitedduetotheirfrequentpositionintheechocardiographicfar
