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UnitedStates43althoughtheEuropeanSocietyofCardiology(ESC)hasindeed
madethatrecommendation.44Althoughmultiplegrassrootslocalscreening
organizationsintheUnitedStateshaveundertakenECGscreeningendeavorsin
ordertoidentifyat-riskindividuals,thisstrategyhasnotyetbeenendorsedby
theAmericanHeartAssociationorotherscreeningorganizationsintheUnited
Statesasamassscreeningstrategy/plan.Ongoingworkiscontinuinginthis
area.FurtherrefinementofECGcriteriainthissettinginordertodefinetrue
“normals”inamulticulturalsocietyintheUnitedStatesisongoinginaneffort
toidentifyabnormalitiesandinordertominimizefalsepositives,avariablebut
importantissueinthesettingofmassECGscreening.45SoalthoughmassECG
screeninghasnotbeenendorsedbyall,asdescribedabove,therecontinuestobe
arefinementofECGcriteriaandacollectionofscreeningdatabymultiple
organizations.Thereareunquestionableexamplesofthisstrategyresultingin
livessaved.Thisstrategyisstilldebatedanddiscussed.Asthesedataare
collected,debated,anddiscussed,thisapproachhopefullywillbesortedoutwith
perhapsmoredefinitivedatawithregardtoitsefficacy.Inthemeantime,the
logisticsandresourcesneededtoadoptaneffectivestrategyonamassbasiswill
ideallybeworkedoutaswedeterminetheoptimalstrategyforprimary
preventionofsuddencardiacarrestandsuddencardiacdeath.
Echocardiographyasaprimaryscreeningtoolhasalsobeensuggestedas
eitheranindependentapproachorincombinationwithECGscreening.46Justas
withECGscreening,itisimportantthattheechocardiographicstudiesbe
performedbyanexperiencedtechnicianandthatthestudiesareinterpretedbyan
experiencedechocardiographer.Itisunlikelythatascreeningechocardiogram
willuncoveralloftheat-riskanatomicabnormalitiesincludingandespecially
congenitalcoronaryarteryabnormalities.Certainly,anechocardiogramwillnot
allowforthediagnosisofelectricalabnormalities/channelopathies.The
resourcesnecessaryandtheperformanceandinterpretationofscreening
echocardiogramshasnotmadethisstrategyonethatiseasytocarryoutandis
certainlynotcurrentlyrecommendedasamassscreeningapproachinandof
itself.

Finally,andbeyondthescopeofthischapter,itisimportanttoconsiderthe
importanceofsecondarypreventionstudieswithregardtosuddencardiacdeath.
Althoughitwouldbethehopethattheabovestrategiescouldpreventsudden
cardiacarrestinallcases,itisveryunlikelythatsuchwillbethecase.Therefore
itiscriticallyimportantthatweadvocateforeducationincardiopulmonary
resuscitationanduseautomaticexternaldefibrillator(CPR-AED)forasmany


peopleaspossible,particularlyhighschoolstudentsandstaff.Suchastrategy
willallowforapopulationthatwillbeabletorecognizecardiacarrestand
intervenebydoingCPRandusinganAED.Suchastrategyhasbeenshownto
increasethedisappointinglylowincidenceoflay-rescuerCPR,aswellasthe
verypooroutcomesassociatedwithout-of-hospitalcardiacarrest.47–50


ScreeningFirst-DegreeRelativesAfter
SuddenCardiacDeathintheYoung
Theincidenceofsuddendeathhasbeenreportedbetween2.7and7.5eventsper
100,000patient-yearsamongyoungpeople(age1to40years)whowere
previouslythoughttobewell.Exactnumbersremainunknown,buttheserates
wouldresultin10,000childrenandyoungadultsexperiencingsudden
unexplaineddeathintheUnitedStateseveryyear.Italy,France,theNetherlands,
andinternationalcommunitieshaverolledoutscreeningprogramsand
registries.51,52Mostofthesedeathsultimatelywillbeattributedtocardiac
causes.Alarge,prospectivepopulation-basedstudyfromAustraliaandNew
Zealanddiagnosedcardiomyopathyonautopsyin16%ofcases.53This
correlatescloselywithaDanishpopulation-basedregistrywithautopsy-based
cardiomyopathyin17%ofcases.54Arrhythmogeniccausesofsuddendeathare
hardertoquantifybecausetheheartstendtobestructurallynormalornearnormal;apotentiallyarrhythmogeniccausewaspresentin45%ofcasesinthe
largeAustralia/NewZealandseries.Inaddition,pathogenicorlikelypathogenic

variantsingenesassociatedwithcongenitalarrhythmiasusceptibilityand
familialcardiomyopathyhavebeendemonstratedin3%to35%ofpostmortem
samplesfromcasesofsuddenunexplaineddeath(seeTable89.1).53,55–71
Becausethesediseasesmaybeinherited,screeningforaffectedfamilymembers
iscritical.Inworkfromseveralcenters,approximately15%offamiliesare
foundtobeaffectedwithaheritablecardiacdiseasewhenfirst-degreerelatives
receivescreeningaftersuddendeathinthefamily.53,72,73
Screeningoffirst-degreerelativesaftersuddenunexplaineddeathis
particularlyimportantbecausetherapycanalterthenaturalhistoryofthese
diseasesamongsurvivingfamilymembers.LongQTsyndromehasbecomethe
prototypicalchannelopathybecauseithasthehighestknownincidenceratein
thepopulationandbecauseβ-blockertherapyforprimarypreventionis
associatedwitha42%to78%reductioninriskofabortedcardiacarrestor
suddencardiacdeath.74–77Amongtheremainingchannelopathiesand
cardiomyopathiestherehavebeensuccesseswithvariouscombinationsof
medications,leftcardiacsympatheticdenervation,ablationtherapy,lifestyle
modification,andavoidanceoftriggeringmedications.Themostcommon
channelopathyandcardiomyopathydiseasesarelongandshortQTsyndrome,