Andersons pediatric cardiology 1178
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depressionintheinferolateralleads.Despitethesecommonfindings,left
ventricularhypertrophyandstrainpatternisneitherhighlysensitivenorhighly
specificforseverestenosis.ThepresenceofQwavesintheleftprecordialleads
isuncommonandmaysuggestassociatedlesions.Theelectricalaxisisusually
normal.
ChestRadiograph
Patientswhopresentwithcriticalaorticstenosisintheneonatalperiodorsevere
aorticstenosisininfancymayhaveradiographicfindingsconsistentwith
cardiomegalywithenlargementoftheleftheartbordersandpulmonaryedema.
Themajorityofolderasymptomaticpatientswillhaveanunremarkablechest
radiographwithnormalcardiothymicsilhouette.Dilationoftheascendingaorta
andcalcificationoftheaorticvalvemaybeevidentonradiographinolderadult
patients.
Echocardiogram
Transthoracicechocardiogramiscurrentlythemainstayforserialassessmentand
decision-makinginchildrenwithaorticvalvedisease.Thevalvarmorphologyis
bestseenfromtheparasternalshort-axisview(Figs.44.15and44.16;Video
44.1),wherethenumberofleafletsandtheirzonesofappositioncanbeseen.53
Theparasternallong-axisviewisusedforassessmentofleafletmobility,aswell
asmeasurementoftheleftventricularoutflowtractandaorticvalveannulus,
whichcanhavevariabledegreesofhypoplasia(seeFigs.44.15and44.16;Video
44.2through44.5).
FIG.44.15 Parasternallong-andshort-axisviewbytransthoracic
echocardiogramthatshowsabifoliate,orbicuspid,aorticvalvewithno
associatedaorticregurgitation.Notethethinleafletsandthehorizontalline
ofclosure.AO,Aorta;LV,leftventricle.
FIG.44.16 Parasternallong-andshort-axisviewbytransthoracic
echocardiogramdemonstratingabifoliateaorticvalvethatismildly
regurgitant.Notethevestigialinterleaflettriangle.AO,Aorta;LA,left
atrium;LV,leftventricle.
Thedegreeofaorticstenosiscanbequantifiedbyechocardiographyin
differentways.Inpediatrics,theDoppler-derivedmeasurementsoftheflow
velocity,aswellasthecalculatedmaximuminstantaneousandmeanpressure
drop,acrosstheaorticvalvearetheprimarymethodsusedtodeterminethe
severityofaorticstenosis.54Thegradientsarederivedfromcontinuouswave
Dopplerinterrogationofflowacrosstheleftventricularoutflowtractinthe
apical,suprasternal,andhighrightparasternallocations,andthehighestvelocity
spectralDoppleristypicallyused(Fig.44.17).Thesemeasurementsarealso
usedaspartofdecision-makingontimingforintervention,inconjunctionwith
leftventricularfunctionandclinicalsymptoms.Thedegreeofstenosisisa
continuumthatextendsfromthosewithouthemodynamicsignificancetosevere
obstructionofflow.Thecurrentrecommendationsofgradingaorticstenosis
severityareshowninTable44.1.
FIG.44.17 Tracingshowingagradientacrosstheoutflowtract
demonstratedbycontinuouswaveDopplerinterrogation.Thisprovidesa
combinationofpeakinstantaneousandmeanDopplergradients.
Table44.1
RecommendationsofGradingofAorticStenosisSeverity
AorticStenosisSeverity
Mild
JetVelocity(m/s)
2.0–2.9
MeanPressureGradient(mmHg)
<20
