Arrhythmias, CardiacElectrocardiographyMyocytes, CardiacArrhythmia, SinusAnti-Arrhythmia AgentsDeath, Sudden, CardiacHeartLong QT SyndromeHeart Conduction SystemTachycardia, VentricularVentricular FibrillationVentricular Premature ComplexesElectrocardiography, AmbulatoryCardiac Complexes, PrematureTachycardiaHeart RateAtrial FibrillationEncainideNAV1.5 Voltage-Gated Sodium ChannelMyocardiumHeart VentriclesCardiac OutputCardiac Pacing, ArtificialEther-A-Go-Go Potassium ChannelsCardiac Surgical ProceduresModels, CardiovascularDeath, SuddenPotassium Channels, Voltage-GatedMoricizineCardiac ElectrophysiologyBradycardiaKCNQ1 Potassium ChannelHeart DiseasesAction PotentialsFlecainideCatheter AblationSodium ChannelsDogsAtrial FlutterHeart AtriaElectrophysiologic Techniques, CardiacTachycardia, SupraventricularTime FactorsMyocardial ContractionDigitalis GlycosidesAtrial Premature ComplexesHeart ArrestChlorofluorocarbons, MethaneMyocardial InfarctionHeart FailureKCNQ Potassium ChannelsAmiodaroneTorsades de PointesMyocardial IschemiaCardiomyopathiesCardiomegalyDefibrillators, ImplantableElectrophysiologyHypokalemiaAconitineCardiac Imaging TechniquesPotassium ChannelsHeart BlockEchocardiographyPericardiumBody Surface Potential MappingAndersen SyndromeElectric CountershockVentricular FunctionTelemetryTreatment OutcomeRyanodine Receptor Calcium Release ChannelRisk FactorsFollow-Up StudiesAutonomic Nervous SystemSyncopeDisease Models, AnimalCardiac CatheterizationHemodynamicsBlood PressurePacemaker, ArtificialCardiac TamponadeCalciumProspective StudiesPatch-Clamp TechniquesMyocardial Reperfusion InjuryBrugada SyndromeCardiomyopathy, DilatedProcainamideCardiotonic AgentsVentricular Function, LeftVentricular DysfunctionMutationEndocardiumTachycardia, Ectopic AtrialPurkinje FibersConnexin 43Calcium SignalingFetal HeartCalcium Channels, L-Type