Heart FailureDeath, Sudden, CardiacHeartDeath, SuddenArrhythmias, CardiacHeart RateMyocytes, CardiacHeart DiseasesDefibrillators, ImplantableCardiac Output, LowElectrocardiographyMyocardiumTachycardia, VentricularVentricular FibrillationStroke VolumeHeart Failure, SystolicSudden Infant DeathCardiomyopathiesCardiomyopathy, DilatedRisk FactorsHeart ArrestCardiac Pacing, ArtificialVentricular Dysfunction, LeftMyocardial InfarctionVentricular Function, LeftEchocardiographyHeart TransplantationTime FactorsCardiac OutputFollow-Up StudiesAdrenergic beta-AntagonistsHeart Failure, DiastolicHemodynamicsLong QT SyndromeCardiomyopathy, HypertrophicMyocardial ContractionTreatment OutcomeProspective StudiesCardiomegalyNatriuretic Peptide, BrainHeart VentriclesVentricular RemodelingAnti-Arrhythmia AgentsHeart Defects, CongenitalRisk AssessmentCardiotonic AgentsMyocardial IschemiaChronic DiseasePredictive Value of TestsBrugada SyndromeHeart Conduction SystemPrognosisHeart Function TestsElectric CountershockCardiac Surgical ProceduresDefibrillatorsElectrocardiography, AmbulatoryRetrospective StudiesTreatment FailureDogsExercise TestHeart AtriaDisease Models, AnimalBiological MarkersCardiopulmonary ResuscitationVentricular DysfunctionProportional Hazards ModelsCoronary DiseaseNAV1.5 Voltage-Gated Sodium ChannelSystoleIncidenceFetal HeartHeart BlockAngiotensin-Converting Enzyme InhibitorsSyncopeHypertrophy, Left VentricularArrhythmogenic Right Ventricular DysplasiaAmiodaronePacemaker, ArtificialHospitalizationCause of DeathAutopsySurvival AnalysisCardiac CatheterizationAutonomic Nervous SystemSeverity of Illness IndexBlood PressureSurvival RateFibrosisDiastoleCohort StudiesElectrophysiologic Techniques, CardiacCardiac Resynchronization TherapyDiureticsCardiac ElectrophysiologyModels, CardiovascularHeart-Assist DevicesKaplan-Meier EstimateHeart ValvesMyocarditis