Sudden cardiac death (SCD) is a sudden, unexpected death caused by loss of heart function (sudden cardiac arrest). Sudden cardiac death is ... NowschedulingCOVID-19vaccinesforages5+,boostersandthirddoses Scheduleyourappointment COVID-19vaccineFAQs GoingtoaClevelandCliniclocation? Newvisitationguidelines Masksrequiredforpatientsandvisitors(evenifyou'revaccinated) Home / HealthLibrary / Disease&Conditions SuddenCardiacDeath(SuddenCardiacArrest) Appointments800.659.7822 Appointments&Locations TalktoaHeartNurse ContactUs Overview SymptomsandCauses ManagementandTreatment Prevention Resources SuddenCardiacDeath(SuddenCardiacArrest) Overview SymptomsandCauses ManagementandTreatment Prevention Resources BackToTop Overview Whataresuddencardiacarrestandsuddencardiacdeath? Suddencardiacdeath(SCD)isasudden,unexpecteddeathcausedbylossofheartfunction(suddencardiacarrest).SuddencardiacdeathisthelargestcauseofnaturaldeathintheUnitedStates,causingabout325,000adultdeathsintheUnitedStateseachyear.Suddencardiacdeathisresponsibleforhalfofallheartdiseasedeaths. Suddencardiacdeathoccursmostfrequentlyinadultsintheirmid-30stomid-40s,andaffectsmentwiceasoftenasitdoeswomen.Thisconditionisrareinchildren,affectingonly1to2per100,000childreneachyear. ElectricalSystemoftheHeart Howissuddencardiacarrest(AV)Nodedifferentfromaheartattack? Suddencardiacarrestisnotaheartattack(myocardialinfarction).Heartattacksoccurwhenthereisablockageinoneormoreofthecoronaryarteries,preventingtheheartfromreceivingenoughoxygen-richblood.Iftheoxygeninthebloodcannotreachtheheartmuscle,theheartbecomesdamaged. Incontrast,suddencardiacarrestoccurswhentheelectricalsystemtotheheartmalfunctionsandsuddenlybecomesveryirregular.Theheartbeatsdangerouslyfast.Theventriclesmayflutterorquiver(ventricularfibrillation),andbloodisnotdeliveredtothebody.Inthefirstfewminutes,thegreatestconcernisthatbloodflowtothebrainwillbereducedsodrasticallythatapersonwillloseconsciousness.Deathfollowsunlessemergencytreatmentisbegunimmediately. Emergencytreatmentincludescardiopulmonaryresuscitation(CPR)anddefibrillation.CPRkeepsenoughoxygeninthelungsandgetsittothebrainuntilthenormalheartrhythmisrestoredwithanelectricshocktothechest(defibrillation).Portabledefibrillatorsusedbyemergencypersonnel,orpublicaccessdefibrillators(AEDs)mayhelpsavetheperson’slife. SymptomsandCauses Whatarethesymptomsofsuddencardiacarrest? Somepeoplemayexperiencearacingheartbeatortheymayfeeldizzy,alertingthemthatapotentiallydangerousheartrhythmproblemhasstarted.Inoverhalfofthecases,however,suddencardiacarrestoccurswithoutpriorsymptoms. Whatcausessuddencardiacdeath? Mostsuddencardiacdeathsarecausedbyabnormalheartrhythmscalledarrhythmias.Themostcommonlife-threateningarrhythmiaisventricularfibrillation,whichisanerratic,disorganizedfiringofimpulsesfromtheventricles(theheart’slowerchambers).Whenthisoccurs,theheartisunabletopumpbloodanddeathwilloccurwithinminutes,ifleftuntreated. Whataretheriskfactorsofsuddencardiacarrest? Therearemanyfactorsthatcanincreaseaperson’sriskofsuddencardiacarrestandsuddencardiacdeath. Thetwoleadingriskfactorsinclude: Previousheartattack(75percentofSCDcasesarelinkedtoapreviousheartattack)-Aperson’sriskofSCDishigherduringthefirstsixmonthsafteraheartattack. Coronaryarterydisease(80percentofSCDcasesarelinkedwiththisdisease)-Riskfactorsforcoronaryarterydiseaseincludesmoking,familyhistoryofcardiovasculardisease,highcholesteroloranenlargedheart. Otherriskfactorsinclude: Ejectionfractionoflessthan40percent,combinedwithventriculartachycardia(seeinformationbelowaboutEF) Priorepisodeofsuddencardiacarrest FamilyhistoryofsuddencardiacarrestorSCD Personalorfamilyhistoryofcertainabnormalheartrhythms,includinglongQTsyndrome,Wolff-Parkinson-Whitesyndrome,extremelylowheartratesorheartblock Ventriculartachycardiaorventricularfibrillationafteraheartattack Historyofcongenitalheartdefectsorbloodvesselabnormalities Historyofsyncope(faintingepisodesofunknowncause) Heartfailure:aconditioninwhichtheheart’spumpingpowerisweakerthannormal.Patientswithheartfailureare6to9timesmorelikelythanthegeneralpopulationtoexperienceventriculararrhythmiasthatcanleadtosuddencardiacarrest. Dilatedcardiomyopathy(causeofSCDinabout10percentofthecases):adecreaseintheheart’sabilitytopumpbloodduetoanenlarged(dilated)andweakenedleftventricle Hypertrophiccardiomyopathy:athickenedheartmusclethatespeciallyaffectstheventricles Significantchangesinbloodlevelsofpotassiumandmagnesium(fromusingdiuretics,forexample),evenifthereisnotorganicheartdisease Obesity Diabetes Recreationaldrugabuse Takingdrugsthatare“pro-arrhythmic”mayincreasetheriskforlife-threateningarrhythmias Suddencardiacdeath(SCD)occursrarelyinathletes,butwhenitdoeshappen,itoftenaffectsuswithshockanddisbelief. Cause: MostcasesofSCDarerelatedtoundetectedcardiovasculardisease.Intheyoungerpopulation,SCDisoftenduetocongenitalheartdefects,whileinolderathletes(35yearsandolder),thecauseismoreoftenrelatedtocoronaryarterydisease. Prevalence: AlthoughSCDinathletesisrare,mediacoverageoftenmakesitseemlikeitismoreprevalent.Intheyoungerpopulation,mostSCDoccurswhileplayingteamsports;inaboutonein100,000toonein300,000athletes,andmoreofteninmales.Inolderathletes(35yearsandolder),SCDoccursmoreoftenwhilerunningorjogging–inaboutonein15,000joggersandonein50,000marathonrunners. Screening: TheAmericanHeartAssociationrecommendscardiovascularscreeningforhighschoolandcollegiateathletes,whichshouldincludeacompleteandcarefulevaluationoftheathlete’spersonalandfamilyhistoryandaphysicalexam.Screeningshouldberepeatedeverytwoyears,andahistoryshouldbeobtainedeveryyear. Menaged40andolderandwomenaged50andoldershouldalsohaveanexercisestresstestandreceiveeducationaboutcardiacriskfactorsandsymptoms. Ifheartproblemsareidentifiedorsuspected,theathleteshouldbereferredtoacardiologistforfurtherevaluationandtreatmentguidelinesbefore Implantablecardioverter-defibrillator(ICD): ForpatientswhohaveagreatriskforSCD,anICDmaybeinsertedasapreventivetreatment.AnICDisasmallmachinesimilartoapacemakerthatisdesignedtocorrectarrhythmias.Itdetectsandthencorrectsafastheartrate. TheICDconstantlymonitorstheheartrhythm.Whenitdetectsaveryfast,abnormalheartrhythm,itdeliversenergy(asmall,butpowerfulshock)totheheartmuscletocausethehearttobeatinanormalrhythmagain.TheICDalsorecordsthedataofeachepisode,whichcanbeviewedbythedoctorthroughathirdpartofthesystemthatiskeptatthehospital. TheICDmaybeusedinpatientswhohavesurvivedsuddencardiacarrestandneedtheirheartrhythmsconstantlymonitored.Itmayalsobecombinedwithapacemakertotreatotherunderlyingirregularheartrhythms. Interventionalproceduresorsurgery: Forpatientswithcoronaryarterydisease,aninterventionalproceduresuchasangioplasty(bloodvesselrepair)orbypasssurgerymaybeneededtoimprovebloodflowtotheheartmuscleandreducetheriskofSCD.Forpatientswithotherconditions,suchashypertrophiccardiomyopathyorcongenitalheartdefects,aninterventionalprocedureorsurgerymaybeneededtocorrecttheproblem.Otherproceduresmaybeusedtotreatabnormalheartrhythms,includingelectricalcardioversionandcatheterablation. Whenaheartattackoccursintheleftventricle(leftlowerpumpingchamberoftheheart),ascarforms.Thescarredtissuemayincreasetheriskofventriculartachycardia.Theelectrophysiologist(doctorspecializinginelectricaldisordersoftheheart)candeterminetheexactareacausingthearrhythmia.Theelectrophysiologist,workingwithyoursurgeon,maycombineablation(theuseofhigh-energyelectricalenergyto“disconnect”abnormalelectricalpathwayswithintheheart)withleftventricularreconstructionsurgery(surgicalremovaloftheinfarctedordeadareaofhearttissue). Educateyourfamilymembers: IfyouareatriskforSCD,talktoyourfamilymemberssotheyunderstandyourconditionandtheimportanceofseekingimmediatecareintheeventofanemergency.FamilymembersandfriendsofthoseatriskforSCDshouldknowhowtoperformCPR. ManagementandTreatment Whatisthetreatmentforsuddencardiacarrest? Suddencardiacarrestcanbetreatedandreversed,butemergencyactionmusttakeplaceimmediately.Survivalcanbeashighas90percentiftreatmentisinitiatedwithinthefirstminutesaftersuddencardiacarrest.Theratedecreasesbyabout10percenteachminutelonger.Thosewhosurvivehaveagoodlong-termoutlook. Prevention 9-1-1 Ifyouwitnesssomeoneexperiencingsuddencardiacarrest,immediatelydial9-1-1orcallyourlocalemergencypersonnelandinitiateCPR.Ifdoneproperly,CPRcansaveaperson’slife,astheprocedurekeepsbloodandoxygencirculatingthroughthebodyuntilhelparrives. IfanAED(AutomatedExternalDefibrillator)isavailable,thebestchanceofrescuingthepatientincludesdefibrillationwiththatdevice.Theshorterthetimeuntildefibrillation,thegreaterthechancethepatientwillsurvive.ItisCPRplusdefibrillationthatrescuesthepatient. Onceemergencypersonnelarrive,defibrillationcanbeusedtorestarttheheart.Thisisdonethroughanelectricshockdeliveredtotheheartthroughpaddlesplacedonthechest. Aftersuccessfuldefibrillation,mostpatientsrequirehospitalcaretotreatandpreventfuturecardiacproblems. Cansuddencardiacarrestbeprevented? Ifyouhaveanyoftheriskfactorslistedabove,itisimportanttospeakwithyourdoctorabouthowtoreduceyourrisk. Keepingregularfollow-upappointmentswithyourdoctor,makingcertainlifestylechanges,takingmedicationsasprescribedandhavinginterventionalproceduresorsurgery(asrecommended)arewaysyoucanreduceyourrisk. Follow-upcarewithyourdoctor: Yourdoctorwilltellyouhowoftenyouneedtohavefollow-upvisits.Topreventfutureepisodesofsuddencardiacarrest,yourdoctorwillwanttoperformdiagnosticteststodeterminewhatcausedthecardiacevent.Testsmayincludeelectrocardiogram(ECGorEKG),ejectionfraction,ambulatorymonitoring,echo-cardiogram,cardiaccatheterizationandelectrophysiologystudy. Ejectionfraction(EF): Ejectionfractionisameasurementofthepercentageofbloodpumpedoutoftheheartwitheachbeat.Ejectionfractioncanbemeasuredinyourdoctor’sofficeduringanechocardiogram(echo)orduringothertestssuchasamultiplegatedacquisition(MUGA)scan,cardiaccatheterization,nuclearstresstestormagneticresonanceimaging(MRI)scanoftheheart. TheEjectionfractionofahealthyheartrangesfrom55to65percent.YourEjectionfractioncangoupanddown,basedonyourheartconditionandtheeffectivenessofthetherapiesthathavebeenprescribed. Ifyouhaveheartdisease,itisimportanttohaveyourEjectionfractionmeasuredinitially,andthenasneeded,basedonchangesinyourcondition.AskyourdoctorhowoftenyoushouldhaveyourEjectionfractionchecked. Reducingyourriskfactors: Ifyouhavecoronaryarterydisease(andevenifyoudonot)therearecertainlifestylechangesyoucanmaketoreducehighbloodpressureandcholesterollevelsandmanageyourdiabetesandweight,therebyreducingyourriskofsuddencardiacarrest. Theselifestylechangesinclude: Quittingsmoking Losingweightifoverweight Exercisingregularly Followingalow-fatdiet Managingdiabetes Managingotherhealthconditions Ifyouhavequestionsorareunsurehowtomakethesechanges,talktoyourdoctor. Patientsandfamiliesshouldknowthesignsandsymptomsofcoronaryarterydiseaseandthestepstotakeifsymptomsoccur. Medications: Tohelpreducetheriskofsuddencardiacarrest,doctorsmayprescribemedicationstopatientswhohavehadheartattacks,orwhohaveheartfailureorarrhythmias.Thesemedicationsmayincludeangiotensin-convertingenzyme(ACE)inhibitors,betablockers,calciumchannelblockersandotherantiarrhythmics.Forpatientswithhighcholesterolandcoronaryarterydisease,statinmedicationsmaybeprescribed. Ifmedicationisprescribed,yourdoctorwillgiveyoumorespecificinstructions. Resources Doctorsvaryinqualityduetodifferencesintrainingandexperience;hospitalsdifferinthenumberofservicesavailable.Themorecomplexyourmedicalproblem,thegreaterthesedifferencesinqualitybecomeandthemoretheymatter. Clearly,thedoctorandhospitalthatyouchooseforcomplex,specializedmedicalcarewillhaveadirectimpactonhowwellyoudo.Tohelpyoumakethischoice,pleasereviewourMillerFamilyHeart,Vascular&ThoracicInstituteOutcomes. ClevelandClinicHeart,Vascular&ThoracicInstituteCardiologistsandSurgeons Choosingadoctortotreatyourabnormalheartrhythmdependsonwhereyouareinyourdiagnosisandtreatment.ThefollowingHeart,Vascular&ThoracicInstituteSectionsandDepartmentstreatpatientswithArrhythmias: SectionofElectrophysiologyandPacing:cardiologyevaluationformedicalmanagementorelectrophysiologyproceduresordevices-CallCardiologyAppointmentsattoll-free800.223.2273,extension4-6697orrequestanappointmentonline. DepartmentofThoracicandCardiovascularSurgery:surgeryevaluationforsurgicaltreatmentforatrialfibrillation,epicardialleadplacement,andinsomecasesifnecessary,leadanddeviceimplantationandremoval.Formoreinformation,pleasecontactus. YoumayalsouseourMyConsultsecondopinionconsultationusingtheInternet. TheHeart,Vascular&ThoracicInstitutehasspecializedcenterstotreatcertainpopulationsofpatients: AtrialFibrillationCenter VentricularArrhythmiaCenter InheritedArrhythmiaClinic Learnmoreaboutexpertswhospecializeinthediagnosisandtreatmentofarrhythmias.Foryoungerpatientswithabnormalheartrhythms: VisitTheCenterforPediatricandCongenitalHeartDiseaseswebsite Findapediatriccardiologist See:AboutUstolearnmoreabouttheSydellandArnoldMillerFamilyHeart,Vascular&ThoracicInstitute. Contact Ifyouneedmoreinformation,clickheretocontactus,chatonlinewithanurseorcalltheMillerFamilyHeart,Vascular&ThoracicInstituteResource&InformationNurseat216.445.9288ortoll-freeat866.289.6911.Wewouldbehappytohelpyou. BecomingaPatient Makeanappointment PlanYourVisit Billing&Insurance VisitorAmenities TreatmentOptions ArrhythmiaTreatments TreatmentGuides AtrialFibrillation VentricularTachycardia AllMillerFamilyHeart,Vascular&ThoracicInstituteTreatmentGuides DiagnosticTests Diagnostictestsareusedtodiagnoseyourabnormalheartbeatandthemosteffectivetreatmentmethod. Diagnostictesting Anatomy Howtheheartbeats Yourheartandbloodvessels Webchats Ourwebchatsandvideochatsgivepatientsandvisitorsanotheropportunitytoaskquestionsandinteractwithourphysicians. AbnormalHeartRhythmwebchatsandvideochats AllMillerFamilyHeart,Vascular&ThoracicInstitutewebchats Videos SuddenCardiacDeathvideowithBruceWilkoff,MD HeartRhythmDisordersandTreatmentsVideos AllMillerFamilyHeart,Vascular&ThoracicInstituteVideos InteractiveTools MillerFamilyHeart,Vascular&ThoracicInstituteInteractiveTools ResourceLinks Recoveryathome SupportGroupsandInformation VisitHealthEssentials ReadarticlesonrhythmdisordersandhealthylivingonHealthEssentials-FollowHeart,Vascular&ThoracicInstitutewebchatsandnewsstoriesonTwitter SubscribetoHeart,Vascular&ThoraciceNews SuddenArrhythmiaDeathSyndromesFoundation Anonprofitorganization,establishedtohelppreventsuddenandunexpectedcardiacdeathinchildrenandyoungadults.* 508ESouthTemple,Ste.20,SaltLakeCity,UT84102 1.800.786.7723 HeartRhythmSociety 1325GStreetNW,Suite400Washington,DC20005 202.464.3400 CPRInformation *Anewbrowserwindowwillopenwiththislink.Theinclusionoflinkstootherwebsitesdoesnotimplyanyendorsementofthematerialonthosewebsitesnoranyassociationwiththeiroperators. WhychooseClevelandClinicforyourcare? Ouroutcomesspeakforthemselves.Pleasereviewourfactsandfiguresandifyouhaveanyquestionsdon’thesitatetoask. Share Facebook Twitter LinkedIn Email Print Getuseful,helpfulandrelevanthealth+wellnessinformation enews ClevelandClinicisanon-profitacademicmedicalcenter.Advertisingonoursitehelpssupportourmission.Wedonotendorsenon-ClevelandClinicproductsorservices. Policy RelatedInstitutes&Services Heart,Vascular&ThoracicInstitute(MillerFamily) Thelatestinformationaboutheart&vasculardisorders,treatments,testsandpreventionfromtheNo.1-rankedheartprogramintheUnitedStates. MoreHeartResources FindmoreHeart&VascularDiseases&Conditionstopics ClevelandClinicisanon-profitacademicmedicalcenter.Advertisingonoursitehelpssupportourmission.Wedonotendorsenon-ClevelandClinicproductsorservices. Policy Morehealthnews+info ShowMore Appointments800.659.7822 Appointments&Locations TalktoaHeartNurse ContactUs Facebook Twitter YouTube Instagram LinkedIn Pinterest Snapchat