Arrhythmias, CardiacDeath, Sudden, CardiacTachycardia, VentricularElectrocardiographyMyocytes, CardiacArrhythmia, SinusVentricular FibrillationAnti-Arrhythmia AgentsDefibrillators, ImplantableElectrocardiography, AmbulatoryHeartHeart Conduction SystemVentricular Premature ComplexesCardiac Pacing, ArtificialCardiac OutputLong QT SyndromeHeart RateElectrophysiologic Techniques, CardiacHeart VentriclesTachycardiaDeath, SuddenCardiac Complexes, PrematureNAV1.5 Voltage-Gated Sodium ChannelMyocardiumCardiac Surgical ProceduresSyncopeMyocardial InfarctionHeart ArrestFlecainideAtrial FibrillationTime FactorsElectric CountershockMyocardial ContractionTorsades de PointesHeart FailureCircadian RhythmTachycardia, SupraventricularFollow-Up StudiesCardiomyopathiesDogsAction PotentialsStroke VolumeCardiomyopathy, DilatedPredictive Value of TestsMyocardial IschemiaCardiac ElectrophysiologyBrugada SyndromeHeart DiseasesModels, CardiovascularProspective StudiesHeart AtriaAmiodaroneEchocardiographyRisk FactorsSignal Processing, Computer-AssistedCardiomegalyVentricular Dysfunction, LeftCatheter AblationEncainideTreatment OutcomeRisk AssessmentVentricular Function, LeftCardiac CatheterizationCardiac TamponadeConnexin 43Adrenergic beta-AntagonistsPericardiumPacemaker, ArtificialSodium ChannelsPeriod Circadian ProteinsArrhythmogenic Right Ventricular DysplasiaVentricular DysfunctionVentricular FunctionDisease Models, AnimalVentricular RemodelingAtrial FlutterElectrophysiologyQuinidineTelemetryEther-A-Go-Go Potassium ChannelsRetrospective StudiesPrognosisEndocardiumKCNQ1 Potassium ChannelWolff-Parkinson-White SyndromeHemodynamicsAutonomic Nervous SystemBundle-Branch BlockRefractory Period, ElectrophysiologicalBlood PressureCardiomyopathy, HypertrophicSuprachiasmatic NucleusBradycardiaCardiac Imaging TechniquesBiological ClocksMyocardial Reperfusion InjuryIsoproterenolHeart Defects, CongenitalAcetanilidesMyoblasts, Cardiac