Andersons pediatric cardiology 1311
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FIG.49.13 Chestradiographshowingthecharacteristicappearancesof
leftjuxtapositionoftheatrialappendages.Notethesigmoidconfigurationof
therightborderofthecardiacsilhouetteandthebulgeintheupperpartof
theleftborder(arrows).RA,Rightatrium;SCV,superiorcavalvein.
Criss-CrossorTwistedHearts,
SuperoinferiorVentricles,andRelated
Conditions
Thelastgroupofheartstobeconsideredarethosewheretherelationshipsofthe
cardiacchambers,orgreatarteries,arenotasexpectedforthegivensegmental
connections.Thesignificanceofthesemalformationshasdiminishedmarkedly
sinceithasbeenappreciatedthatsegmentalconnectionscannot,andshouldnot,
beinferredfromabnormalrelationshipsofcardiacstructures.However,the
abnormalrelationshipsinthemselvescanstillbeaconfusingfeature.Themost
commonlyencounterediscriss-crossingor,moreprecisely,twistingoftheheart
aroundthelongaxisoftheheart,resultinginanunexpectedrelationshipofthe
ventriclesandarterialtrunks(Fig.49.14).24,25However,thereareother
arrangementsthatshowanabnormalventricularrelationshipwithoutcrossingor
twistingoftheventricularinlets.Therearethreemutuallyexclusivemechanisms
thatcanproduceabnormalventricularrelationshipsforthegivensegmental
connections,namely,twisting,tilting,androtation.Bytwisting,wemeanaspiral
relationshipoftheatriumsandventriclesinwhichthecardiacchambersand
arterialtrunksarealignedandarrangedasiftheheartweretwistedclockwise,or
anticlockwise,byahandplacedonthecardiacapexwiththevenousconnections
oftheheartmaintainedintheirnormalpositions(Fig.49.15).Tilting,incontrast,
producesasuperoinferiorrelationshipoftheventricles,withtheparallelaxesof
theventricularinletandatrioventricularjunctionsbeingpreservedasiftheapex
oftheheartweresimplyliftedbyahandplacedontheapex(Fig.49.16).
Rotationdescribesthemuchrarercondition,inwhichthecardiacchambers,
arterialtrunksandcavalveinsareallabnormallyorientedwithinthethorax,asif
theentireheartwererotatedasablockarounditslongaxis.Thisproducesthe
“topsy-turvy”arrangement(Fig.49.17).
FIG.49.14 Reconstructionofthecavitiesfromacomputedtomographic
datasetshowingtheunusualrelationshipsproducedbytwistingofthe
ventricularmassinapatienthavingusualatrialarrangement,concordant
atrioventricularconnections,anddiscordantventriculoarterialconnections.
Themorphologicallyrightventricleispositionedsuperiorlyandleftward
relativetothemorphologicallyleftventricle,withtheaortainaleftward
position.Thecylindersinsertedintheatrioventricularjunctionsrevealthe
twistingthatistheessenceofthelesion.
