Andersons pediatric cardiology 683

FIG.26.10 Heartwithisomerismoftheleftatrialappendagesandquasimirrorimagevenousrelationships.(A–B)Bilateraltubularappendages
haveanarrowjunction(redarrows)withtheatrialvestibule.(A)The
superiorcavalveinisleft-sided.(B)Apersistentrightsuperiorcavalvein
drainedtothecoronarysinus(notseen).Theredstarindicatestheright
pulmonaryartery.(C)Posteroinferioraspectdemonstratingtheleft-sided
superiorandinferiorcavalveinsandtheright-sidedpersistentright
superiorcavalvein(yellowarrow)drainingtotheleft-sidedcoronarysinus
(yellowdots).(D)Therightventricleisopenedinclamshellfashiontoshow
thecommonatrioventricular(AV)valve.Theapexofthisheartwastothe
right,andthereisright-handtopology.


FIG.26.11 Isomerismoftherightatrialappendageswithquasi-mirror
imagevenousrelationships.Theopenedatriumsexhibitpectinatemuscles
tothecrux.(A)Therightandleftpulmonaryveinsdraintotheright-sided
atriuminthisheartwithanatrioventricularseptaldefectandanatrialseptal
defect.(B)Thesuperiorandinferiorcavalveinsdraintotheleft-sided
atrium.Notetheterminalcrest(star).

FIG.26.12 Bilateralappendagesofrightmorphology(notethepectinate
musclesextendingtothecruxonbothsides),withthepulmonaryveins
drainingthroughacentralfibrousconfluence.Thisisanatomically
anomalous.


FIG.26.13 Heartwithallthepulmonaryveinsreturningtotheright-sided
atrium,whichhasanappendageofrightmorphology.Inanatomicterms,
thisistotallyanomalouspulmonaryvenousconnection.Notetheabsence
ofthecoronarysinus.

Totallyanomalouspulmonaryvenousconnection,alongwithabsenceofthe

coronarysinus,isthereforethedistinguishingatrialfeatureofheartswith
isomericrightatrialappendages.Incontrast,ananomalousconnectionofthe
inferiorcavalveinusuallydrawsattentiontothepotentialpresenceofisomeric
leftatrialappendages.Inthissetting,thereisabsenceofthesuprarenalsegment
oftheinferiorcavalvein,withtheabdominalsegmentofthecavalvein
continuingthroughtheazygosvenoussystem(Fig.26.14)todraintoeitherthe
right-orleft-sidedsuperiorcavalvein.Inpatientswithleftisomerism,both
accessoryvenoussystemsarestrictly“hemiazygos,”sincethehemiazygosvein
isamorphologicallyleftstructure.Itissimpler,nonetheless,todescribe
communicationviatheazygosvenoussystemtoaccountfortheright-sidedor
left-sidedlocationoftheanomalousvenouschannel.Azygoscontinuationcanbe
foundinthesettingofrightisomerismbutisveryrare.Althoughthesuprarenal
segmentoftheinferiorcavalveinisabsent,aconfluentsuprahepaticvenous
channelcanbefoundinuptoone-thirdofthepatientswithisomericleftatrial
appendages.