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 FibrillationElectric CountershockTime FactorsMyocardial ContractionTorsades de PointesHeart FailureCircadian RhythmTachycardia, SupraventricularCardiomyopathiesDogsFollow-Up StudiesAction PotentialsStroke VolumeCardiomyopathy, DilatedPredictive Value of TestsMyocardial IschemiaCardiac ElectrophysiologyBrugada SyndromeHeart DiseasesModels, CardiovascularHeart AtriaAmiodaroneProspective StudiesEchocardiographySignal Processing, Computer-AssistedCardiomegalyVentricular Dysfunction, LeftRisk FactorsCatheter AblationEncainideRisk AssessmentVentricular Function, LeftTreatment OutcomeCardiac CatheterizationCardiac TamponadeConnexin 43Adrenergic beta-AntagonistsPericardiumPacemaker, ArtificialSodium ChannelsPeriod Circadian ProteinsArrhythmogenic Right Ventricular DysplasiaVentricular DysfunctionVentricular FunctionVentricular RemodelingAtrial FlutterElectrophysiologyQuinidineTelemetryDisease Models, AnimalEther-A-Go-Go Potassium ChannelsPrognosisEndocardiumKCNQ1 Potassium ChannelWolff-Parkinson-White SyndromeHemodynamicsAutonomic Nervous SystemBundle-Branch BlockRetrospective StudiesRefractory Period, ElectrophysiologicalBlood PressureCardiomyopathy, HypertrophicSuprachiasmatic NucleusBradycardiaCardiac Imaging TechniquesBiological ClocksMyocardial Reperfusion InjuryIsoproterenolHeart Defects, CongenitalAcetanilidesMyoblasts, Cardiac