Andersons pediatric cardiology 595
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LaboratoryRequirements
Environment
Adequatespaceandenvironmentalcontrolsareimportanttoensureasuccessful
exercisetest.Thechildshouldbemadetofeelcomfortableandrelaxed,which
willimproveexerciseperformance.Sufficientspaceisneededtoaccommodate
thevariousergometersandmonitoringequipment,includingemergency
resuscitationequipment,whilemaintainingadequatespacetoaccessthepatient
inemergencysituations.Aminimumof250squarefeetofspaceisrequired,
with500squarefeetormorewhenmultipleworkstationsareused.28
Theclimateofthelaboratorymustbewellcontrolledtoallowproper
thermoregulationduringtheexercisetest.Theroomshouldbewellventilated,
andtemperaturesshouldberegulatedbetween20°Cand23°C,28,29atemperature
rangethatpermitsthepatienttobecomfortableatrestbutstillallowsfor
adequatedissipationofheatduringexercise.Humidityshouldbeapproximately
50%toensurefreeperspirationduringexercise.29
Exerciselaboratoryconditionsmaybeintentionallyalteredtosimulatethe
environmentinwhichthepatientorreferredathletehasbeenexperiencing
symptoms.Thelaboratoryshouldbechildfriendly.Forexample,wallposters
andtelevisionmonitorswithappropriateprograminghaveprovenusefulin
minimizingpatientanxietyandboredom.
SafetyPrecautions
Exercisetestinghasbeenperformedinchildrenwithverylowrisk,eveninthose
whohavecomplexcardiovasculardisease.30,31Althoughsignificant
complicationsofexercisetestingarerare,propersafetyprecautionsareessential.
Keystaffusuallyincludeatleastonephysicianwhoiswelltrainedinpediatric
exercisetesting.Aphysiciandoesnotneedtobedirectlypresentfortesting
patientsdeemedtobeatrelativelylowrisk29,32butshouldbepresentatthe
testingofanychilddeemedtobeatincreasedriskofacomplication,suchasa
childwithahistoryoflife-threateningarrhythmiaorsyncope.TheAmerican
HeartAssociationhaspublishedguidelinesforpatientswhoareatlowriskfor
exercisecomplicationsandrequireaphysicianavailablebutnotphysically
present(Box23.1).32Theriskforeachpatientmustbeindividuallyassessed.
Ideally,twostaffmemberstrainedinexercisetestingshouldbepresentforall
tests.Allexercisephysiologistsorexercisetechniciansshouldbefamiliarwith
pediatricexercisetesting,andatleastoneofthesepersonnelshouldbetrainedin
pediatricadvancedlifesupport.Awell-stockedemergencyresuscitationcart,
defibrillator,systemfordeliveryofoxygen,andsuctionapparatusarealso
essential.32
Box23.1
IndicationsforExerciseTestinginChildren
ThatMayNotRequireaPhysician'sPresence
1.Assessmentofworkingcapacityinhealthychildrenforresearch.
2.Evaluationsofchestpainoflikelynoncardiacorigin.
3.Postoperativefollow-upofpatientswithgoodhemodynamicstoassess
workingcapacityorrehabilitationscreen.
4.Evaluationofisolatedprematureatrialcontractionsorpremature
ventricularcontractionsinahealthychildwithanormalQTc.
5.Routinefollow-upofknownarrhythmiasorpacemakerfunction.
6.Kawasakidiseaseorothercoronaryabnormalitieswithoutaknown
historyofischemia.
7.Asymptomatichemodynamicallyinsignificant(mildormoderate)aortic
stenosis.
8.Evaluationofasymptomaticcongenitaloracquiredcardiacmalformations
withoutassociatedfeaturesofincreasedrisk(e.g.,thepresenceof
pulmonaryvascularobstructivedisease,outflowtractobstruction,severe
ventriculardysfunction,cyanosis).
ModifiedfromWashingtonRL,BrickerJT,AlpertBS,etal.Guidelinesfor
exercisetestinginthepediatricagegroup.FromtheCommitteeon
AtherosclerosisandHypertensioninChildren,CouncilonCardiovascular
DiseaseintheYoung,theAmericanHeartAssociation.Circulation.
1994;90:2166–2179.
PreparationofPatients
Educationandpreparationofthechildrenbeforeandduringtheirtestare
probablythemostimportantfactorsinsuccessfultesting.Athorough
explanationofthetestingprocedureresultsinbettercomplianceandeffort,
especiallyinyoungerchildren.Childrenshouldavoidheavymealsfor
approximately2hourspriortothetestandwearappropriateclothing,suchas
shorts,T-shirts,andathleticshoes.Properpreparationoftheskinhelpstoensure
anadequateelectrocardiographicsignal.33Superficialabrasionshouldbe
performedtoremovethetoplayerofepidermisandenhancetheelectricalsignal.
Electrodesshouldbelargeenoughtoprovidegoodcontactwiththeskin.
Thepatientshouldbeinstructedintheprocedurestobeusedduringthe
exercisetest.Theseincludeproperuseofthetreadmillorcycleergometerand
theuseofhandsignalstoconveytheleveloffatigue,distress,orsymptoms.
Scalesofperceivedexertion,suchastheBorgscale,canbeusefulin
communicatingwiththepatientduringthestudy.Suchscalesallowthose
conductingthetestingtoestimatewhenthechildislikelytoreachmaximal
effort(Fig.23.8).34Specialattentionshouldbegiventomaneuvers,suchas
spirometryorinertgasrebreathingcardiacoutputassessment,thatrequireproper
techniqueandcooperationfromthepatient.
FIG.23.8 Childundergoingexercisetesting.Heindicatesnonverballyhis
levelofperceivedexertionbypointingtotheappropriatenumberonthe
Borgscale.Thestaffusesthisinformationtodeterminetheprojectedtime
toexhaustion.
