Andersons pediatric cardiology 1810

FIG.69.11 Fistulouscommunicationbetweenthehypoplasticleft
ventricularcavityandtheectaticcircumflexarteryinaheartobtainedat
transplantationfromapatientwithhypoplasticleftheartsyndromewith
mitralstenosis.


PulmonaryAtresiaWithIntactVentricular
Septum
Themorphologicvariationsfoundinthesettingofpulmonaryatresiawithan
intactventricularseptumshowhowthesamelesioncanbefoundaseithera
functionallyuniventricularorafunctionallybiventricularentity.Theoverall
morphologicfeaturesofpulmonaryatresiafoundwithanintactventricular
septumwasdiscussedinChapter43.Therewestressedhowmuralhypertrophy
wasthekeytophenotypicvariation,althoughsomeofthepatientswiththeworst
clinicalprognosishadventriculardilation,asopposedtocavitaryhypoplasia,as
theirmajorfeature.Thesepatientspresentwith“wall-to-wall”heartsandcould
becandidatesforconversiontotheFontancirculation.Morefrequently,itisthe
patientshavinggrossmuralhypertrophywhowillbemostlikelytobeput
forwardfortreatmentusingtheFontanapproach.Inthesepatients,withthe
ventricularseptumbeingintact,therightventriclepossessesitsexpectedinlet,
apicaltrabecular,andoutletcomponents.16Themuralhypertrophy,however,is
sufficientlygreattohavesqueezedoutthecavitiesofboththeapicalandoutlet
components.Inconsequence,theventricularcavityisrepresentedeffectivelyby
onlytheinlet,withthetricuspidvalvebeinggrosslyhypoplasticinkeepingwith
thediminishedsizeoftheventricle(Fig.69.12)and,asinthosewithtricuspid
atresia,necessitatingasurgicalstrategyleadingtoconstructionoftheFontan
circulation.Theobliterationofthesubpulmonaryinfundibulummeansthatitis
unusualtofindevidenceofanyremnantsofthepulmonaryvalvarleaflets.
Instead,triradiatingsinusesareseenwithinthepulmonaryroot(seeFig.69.12,
right).Fistulouscommunicationsbetweenthehypoplasticrightventricular
cavityandtheepicardialcoronaryarteriesaremorecommonlyfoundinthese

patients.17Thechangesinducedinthecoronaryarteries,whichbecomeectatic,
contributestillfurthertothepoorclinicalprognosis.Suchheartsarefunctionally
univentriculardespitebeinganatomicallybiventricular(Fig.69.13).


FIG.69.12 Functionallyuniventricularendofthespectrumoflesions
foundinthesettingofpulmonaryatresiawithanintactventricularseptum.
Left,Themuralhypertrophyhassqueezedoutthecavitiesoftheapical
trabecularandoutletventricularcomponents,leavingthecavityeffectively
representedbythehypoplasticinletcomponent.Whenviewedfromthe
aspectofthepulmonarytrunk(right),thereisminimalevidenceofthe
pulmonaryvalvarleaflets,withtherootrepresentedbythetriradiating
valvarsinuses.