SyndromeArrhythmias, CardiacDeath, Sudden, CardiacMyocytes, CardiacTachycardia, VentricularElectrocardiographyHeartDefibrillators, ImplantableCardiac OutputVentricular FibrillationElectrocardiography, AmbulatoryDown SyndromeMetabolic Syndrome XLong QT SyndromeBrugada SyndromeCardiac Pacing, ArtificialAnti-Arrhythmia AgentsCardiac Surgical ProceduresDeath, SuddenSyncopeHeart Conduction SystemCircadian RhythmHeart VentriclesNAV1.5 Voltage-Gated Sodium ChannelHeart ArrestElectrophysiologic Techniques, CardiacHeart RateMyocardial InfarctionMyocardiumTime FactorsPredictive Value of TestsNephrotic SyndromeFollow-Up StudiesMyocardial ContractionHeart FailureSjogren's SyndromeStroke VolumeRisk FactorsProspective StudiesVentricular Premature ComplexesCardiomyopathiesCardiomyopathy, DilatedHeart DiseasesCardiomegalyTreatment OutcomeRisk AssessmentCardiac TamponadePeriod Circadian ProteinsTachycardiaVentricular Dysfunction, LeftCardiac ElectrophysiologyCardiac CatheterizationElectric CountershockEchocardiographyTurner SyndromeFlecainideAbnormalities, MultipleWolff-Parkinson-White SyndromeSignal Processing, Computer-AssistedCardiac Complexes, PrematureMutationTorsades de PointesPrognosisMyocardial IschemiaSuprachiasmatic NucleusVentricular Function, LeftAcute Coronary SyndromeRetrospective StudiesDogsMyelodysplastic SyndromesDisease Models, AnimalAction PotentialsVentricular RemodelingCushing SyndromeModels, CardiovascularPhenotypeBiological ClocksPolycystic Ovary SyndromeMyoblasts, CardiacDiGeorge SyndromeCardiac Imaging TechniquesWilliams SyndromePedigreeAdrenergic beta-AntagonistsCardiac MyosinsBundle-Branch BlockHeart Defects, CongenitalBlood PressureCryptochromesSodium ChannelsHeart AtriaCardiac GlycosidesKCNQ1 Potassium ChannelEncainideHemodynamicsHorner SyndromePacemaker, ArtificialCardiac Output, LowSurvival AnalysisVentricular Function