Death, Sudden, CardiacDeath, SuddenArrhythmias, CardiacCause of DeathMyocytes, CardiacDefibrillators, ImplantableCell DeathElectrocardiographyTachycardia, VentricularSudden Infant DeathVentricular FibrillationHeart ArrestLong QT SyndromeHeartCardiomyopathy, HypertrophicRisk FactorsCardiac OutputBrugada SyndromeDefibrillatorsHeart DiseasesCardiomyopathiesHeart Conduction SystemDeathElectric CountershockMyocardial InfarctionAnti-Arrhythmia AgentsCardiac Surgical ProceduresMyocardiumCardiac Pacing, ArtificialTime FactorsCardiopulmonary ResuscitationHeart FailureElectrocardiography, AmbulatoryFollow-Up StudiesRisk AssessmentHeart RateAutopsyNAV1.5 Voltage-Gated Sodium ChannelHeart VentriclesProspective StudiesSyncopeArrhythmogenic Right Ventricular DysplasiaEchocardiographyCardiac ElectrophysiologyTreatment OutcomeCardiomegalyRomano-Ward SyndromeStroke VolumeKCNQ1 Potassium ChannelRetrospective StudiesPredictive Value of TestsElectrophysiologic Techniques, CardiacMyocardial IschemiaVentricular Dysfunction, LeftCardiomyopathy, DilatedCoronary Vessel AnomaliesMyocardial ContractionEther-A-Go-Go Potassium ChannelsIncidenceOut-of-Hospital Cardiac ArrestAmiodaroneForensic PathologyCardiomyopathy, Hypertrophic, FamilialPrognosisAdrenergic beta-AntagonistsCardiac TamponadeAutonomic Nervous SystemCoronary DiseaseVentricular Function, LeftCardiac CatheterizationSportsDogsCoronary Artery DiseaseAjmalineAthletesSurvival AnalysisTroponin TSurvival RateHypertrophy, Left VentricularModels, CardiovascularBundle-Branch BlockCohort StudiesRiskBrain DeathDisease Models, AnimalTachycardiaKaplan-Meier EstimateUnited StatesMutationEmergency Medical ServicesResuscitationHemodynamicsSyndromeHeart TransplantationVentricular RemodelingProportional Hazards ModelsFibrosisHospitals, StateJervell-Lange Nielsen SyndromeChannelopathies