Andersons pediatric cardiology 1314
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instances,thereisdisharmonybetweentheconnectionsofthesegmentsandthe
topologicarrangementoftheventricularmass.26,27Theseheartsproducea
differentvariantofthecriss-crossheart,whichcannotsimplybeexplainedon
thebasisofrotationoftheventricularmass.
Intheexampleswehaveseen,theatrialchamberswerearrangedintheusual
fashion.Therightatriumconnectedtothemorphologicallyrightventricle,which
wasleft-sidedrelativetothemorphologicallyleftventricle(Fig.49.21).Theleft
ventriclewasconnectedtotheleftatrium.However,despitetheconcordant
atrioventricularconnectionstherewaslefthandventriculartopology.Inaddition,
therewasdoubleoutletfromthemorphologicallyrightventricleandleft-sided
juxtapositionoftheatrialappendages.Itisintheseparticularlyrareinstances
thatitisnecessarytospecifythetopologyofthecardiacsegmentsinadditionto
theidentifiedatrioventricularconnections.Providedthatallthesefeaturesare
recognized,andaccountedforseparately,thereshouldbelittleroomfor
confusionormisunderstanding,irrespectiveofthespecificwordsusedfortheir
description.However,theterm“criss-cross”itselfdescribesaparticular
relationshipoftheventricularinlets.Indeed,theatrioventricularvalvarplanes
cancrosseachotherevenwhenbothvalvesopentothesameventricle(Fig.
49.22).28Simplydescribingthetwistedatrioventricularconnectionsdoesnot
accountforthemorphologyoftheentireheart.Fullsequentialsegmental
descriptionisneededforthatpurpose.
FIG.49.21 Heartwithaveryrareformofcriss-crossmalformation.(A)
Theatriumsareconnectedtomorphologicallyappropriateventricles;in
otherwords,theatrioventricularconnectionsareconcordant,withthepink
probepassingfromtheusuallyarrangedrightatriumtothemorphologically
rightventricle.(B)Themorphologicallyrightventricleisleft-sided,and
givesrisetobotharterialtrunksinthesettingofbilateralinfundibulums.
Thereisleft-handventriculartopology,despitethepresenceofusualatrial
arrangementandconcordantatrioventricularconnections.Providingthat
thesegmentalconnectionsaredescribedseparatelyfromtheventricular
topology,thisarrangementshouldnotcauseconfusion.LA,Leftatrium;LV,
leftventricle;PT,pulmonarytrunk;RV,rightventricle.
FIG.49.22 Magneticresonanceimagesfromapatientwithdouble-inlet
rightventricleshowinghowtheatrioventricularvalvescrosseachotheras
theyenterthedominantrightventricle(arrows),producingtwisteddoubleinletatrioventricularconnection.LA,Leftatrium;RA,rightatrium;RV,
dominantrightventricle.
Incomparisonwiththepotentialproblemsencounteredwithcriss-crosshearts,
fewdifficultiesshouldbeposedbyventriclesthatarearrangedinthe
superoinferiorortheupstairs-downstairsmanner.Thisfindingsimplyreflectsa
tiltingoftheventricularmassalongitslongaxis(seeFig.49.16).Superoinferior
ventriclesareusuallydescribedinthesettingofcongenitallycorrected
transposition,whereinmostinstancestheventriclesarearrangedinside-by-side
fashion.Tiltingoftheventricularmasstoeithersideproducesastackingeffect
oftheventriclesoneontopoftheother.Aswithtwistedatrioventricular
connections,superoinferiorventriclesareoftenseeninthepresenceofstraddling
and/oroverridingatrioventricularvalves.Aswasalsothecasewiththetwisted
arrangement,notinganupstairs–downstairsorsuperoinferiorarrangementdoes
notdescribethecompleteheart,butonlyaparticularventricularrelationship.
Sequentialsegmentaldescriptionismandatoryforfullcategorizationofthe
heartsshowingthisabnormality.
Thereisafurthervariationtobenotedinthesettingoftheseunusual
ventricularrelationships.FirstdescribedbyFreedomandhiscolleaguesintheir
textbookofangiography,theentityhasnowbeendiagnosedduringfetallife,and
inafamilialsetting.29Calledthetopsy-turvyarrangement,theessentialfeature
isrotationofthewholeheartarounditslongaxis,withsuperoinferior
relationshipsoftheatriumsandventricles(seeFig.49.17),butwithouttwisting
oftheaxesoftheatrioventricularconnections.Asthearterialroots,aswellas
theaorticarchandarterialduct,aredisplaceddownwardasaconsequenceof
rotationofthewholeheart,thebranchesoftheaorticarchandthesuperiorcaval
veinareelongated(Figs.49.23and49.24).Moreimportantly,thetracheais
elongatedandtheleftbronchusisseverelycompressedbythelow-lyingaortic
archandarterialduct(Fig.49.25).ThegroupfromTorontoinitiallydescribed
twocasesofthetopsy-turvyheart,andsubsequentlyencounteredanadditional
example.Therehavenowbeenfiveadditionalcasesdescribedintheliterature,
allofMiddleEasternorSouthAsianorigin,whichsuggestsagenetic
backgroundforthisraremalformation.30,32
FIG.49.23 Magneticresonanceimagesshowingtheessenceofthe
