Andersons pediatric cardiology 1312
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FIG.49.15 Essenceofthecriss-crossheart,betterdescribedintermsof
twistedatrioventricularconnections.Thespatialrelationshipofthecardiac
chambersandarterialtrunkscanbestbeunderstoodbyimaginingthatthe
heartistwistedclockwiseoranticlockwisebytherighthandoftheobserver
placedonthecardiacapex,withthelefthandholdingtheposterioraspect
oftheatriums.Thedirectionoftwistingisinsuchawaytoplacetheright
ventricularinletupwardandforward.Withagreaterdegreeoftwisting,the
entiretyoftheaxesoftheatrioventricularconnectionsseemtobecrisscrossing.Theupperpanelshowsthearrangementintranspositionwith
concordantatrioventricularconnections,whilethelowerpanelshowsthe
situationinthesettingoftheusualarrangementandcongenitallycorrected
transposition.Inbothinstances,iftheventricularmassbecomestwisted,
themorphologicallyrightventricle(RV)assumesananteriorlocation.Inthe
settingofregulartransposition,theaorticvalveispositionedanteriorandto
theleft,ratherthantotherightasisexpected.Thereversearrangementis
seeninthesettingofcongenitallycorrectedtransposition.Thetwisting,in
mostinstances,doesnotchangethesegmentalconnections.Ao,Aorta;
LV,leftventricle;LA,leftatrium;PT,pulmonarytrunk;RA,rightatrium.
FIG.49.16 Mechanismproducingsuperoinferiorventriclesinthesetting
ofcongenitallycorrectedtransposition.Thereistiltingoftheventricular
masstoeithertherightortheleft,withthedrawingshowingtiltingtothe
left.Oftensuchtiltingiscombinedwithatwistingabnormality.The
arrangementisalsodescribedas“upstairs-downstairs”heart.Ao,Aorta;
LA,morphologicallyleftatrialappendage;LV,morphologicallyleftventricle;
PT,pulmonarytrunk;RA,morphologicallyrightatrium;RV,morphologically
rightventricle.
FIG.49.17 Rotationoftheheartalongitslongaxisproducesthe“topsyturvy”arrangement.Ao,Aorta;LA,morphologicallyleftatrialappendage;
LV,morphologicallyleftventricle;PT,pulmonarytrunk;RA,morphologically
rightatrium;RV,morphologicallyrightventricle;SVC,superiorcavalvein.
Itistwistingthatistheessentialfeatureoftheso-calledcriss-crossheart
(Figs.49.18to49.20).Thecommoncharacteristicsofthetwistedheartinclude
lossofnormalparallelaxesofventricularinlets.Thereisalsoangulationofthe
