Andersons pediatric cardiology 1303
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AbnormalPositionsand
RelationshipsoftheHeart
Shi-JoonYoo,RobertH.Anderson
Abstract
Theextremeexampleofanabnormallocationoftheheartisits
exteriorizationfromthethoraciccavity,inotherwordsectopiacordis.This
lesionisassociatedwithvariabledeficiencyofthebodywallinthemidline,
withfurthervariationintermsoftheintegrityoftheoverlyingskin.An
abnormallocationisalsofoundwhenpartsofdualheartsarejoined
togetherinthesettingofconjoinedtwins.Theheart,nonetheless,canbe
positionedwithinthechestinunexpectedfashion,oritsapexcanshowan
abnormalorientationrelativetotheremainderofthecardiacmass.These
findings,alongwithunexpectedrelationshipsofchambersorgreatvessels
withintheheart,canallleadtoconsiderablediagnosticproblems,which,in
thepast,createdconsiderableconfusion.Wehavealreadyoutlinedour
philosophyandapproachtothesesituationsinChapter1.Werecommend
revisitingthischapterforrefreshmentconcerningourgroundrules.This
chaptersynthesizesthevalueoftheseconceptsinthesettingofthevarious
abnormallypositionedhearts,alongwiththefindingofunexpected
intracardiacrelationships.Thechapterbeginswithadiscussionofthemajor
problemsproducedbyectopiacordisinitsvariousguises,includingtherole
ofcleftingorabsenceofthesternum.Abriefaccountisthenprovidedof
congenitalabsenceofthepericardium.Wethensummarizethecardiac
problemsencounteredinthesettingofconjoinedtwins.Whenconsidering
abnormalpositions,wesuggestthatitisbestsimplytodescribethelocation
oftheheartwhenitoccupiesanunexpectedpartofthethoraciccavity,or
whenitsapexisabnormallypositioned,ratherthancreatingarcaneLatinate
terminologies.Wethendiscusstheproblemsproducedby,andthe
anomaliesassociatedwith,juxtapositionoftheatrialappendages.We
concludewithaconsiderationofthearrangementsvariouslydescribedas
criss-crosshearts,superoinferiorventricles,orthetopsy-turvyarrangement.
Keywords
Ectopiacordis;conjoinedtwins;juxtaposition;dextrocardia;
dextroversion;criss-crosshearts;twistedhearts;superoinferior
ventricles;topsy-turvyheart
Introduction
Anabnormallypositionedheartisnotinitselfamalformationofmajor
significance.Suchabnormalpositioning,forexample,canbesecondarytoa
deformityordefectofthechestwall,suchaspectusexcavatumorcarinatum.
Theexceptionsaretheextremeexamplesofexteriorizationoftheheart,usually
describedasectopiacordis,orunionofpartsoftheheartinthesettingof
conjoinedtwins.Aheartunusuallypositionedwithinthechest,anabnormal
orientationofthecardiacapex,orthefindingofunexpectedrelationshipsof
structureswithintheheart,nonetheless,canallleadtoconsiderablediagnostic
problems.Inthepast,suchsituationscreatedsignificantconfusion.Our
philosophyandapproachtothesesituationshavebeenoutlinedinChapter1.
Thosewhohavenotstudiedthischapterindetailshould,perhaps,returnfor
refreshmentconcerningourgroundrules.Thischapterseekstosynthesizethe
valueofourconceptsinthesettingofabnormallypositionedhearts,alongwith
thefindingofunexpectedintracardiacrelationships.Westartbydiscussingthe
situationencounteredinthesettingofabsenceorcleftingofthesternum,which
canbeconsideredavariantof“ectopia.”Wethenaddressthemuchmore
significantproblemsproducedbyatrulyextrathoracicpositionoftheheart,or
“classic”ectopiacordisinitsvariousdegrees.Wefollowthiswithabrief
accountofcongenitalabsenceofthepericardium.Wethensummarizethe
cardiacproblemsencounteredinthesettingofconjoinedtwins.Thelocationof
theheartinanunexpectedpartofthethoraciccavity,ortheorientationofits
apexinadisharmoniousfashion,thenexttopicsforconsiderationarebestdealt
withsimplybydescription.Havingsuggestedsuchsimpledescriptions,wethen
discusstheproblemsproducedby,andtheanomaliesassociatedwith,
juxtapositionoftheatrialappendages.Weconcludewithaconsiderationofthe
arrangementsvariouslydescribedascriss-crossortwistedhearts,superoinferior
ventricles,orthetopsy-turvyarrangement.
