Arrhythmias, CardiacArrhythmia, SinusElectrocardiographyMyocytes, CardiacTachycardia, VentricularAnti-Arrhythmia AgentsDeath, Sudden, CardiacVentricular FibrillationHeartVentricular Premature ComplexesHeart Conduction SystemTachycardiaElectrocardiography, AmbulatoryHeart VentriclesHeart RateCardiac Pacing, ArtificialCardiac Complexes, PrematureCardiac OutputLong QT SyndromeAtrial FibrillationMyocardiumCardiac Surgical ProceduresElectrophysiologic Techniques, CardiacDefibrillators, ImplantableTachycardia, SupraventricularAtrial FlutterCatheter AblationDogsHeart AtriaHeart DiseasesVentricular DysfunctionTime FactorsMyocardial InfarctionMyocardial ContractionNAV1.5 Voltage-Gated Sodium ChannelMyocardial IschemiaFlecainideAction PotentialsElectric CountershockCardiomyopathiesModels, CardiovascularHeart ArrestTorsades de PointesHeart FailureAmiodaroneBradycardiaCardiomegalyEchocardiographyDigitalis GlycosidesMyocardial Reperfusion InjuryCardiac ElectrophysiologyDeath, SuddenCardiac CatheterizationFollow-Up StudiesHeart BlockTreatment OutcomePericardiumElectrophysiologyHemodynamicsEther-A-Go-Go Potassium ChannelsBody Surface Potential MappingPacemaker, ArtificialCardiomyopathy, DilatedAconitineVentricular Function, LeftCardiac TamponadeAtrial Premature ComplexesVentricular FunctionPropafenoneBlood PressureDisease Models, AnimalSyncopeProspective StudiesSodium ChannelsRisk FactorsVoltage-Sensitive Dye ImagingHeart Defects, CongenitalTelemetryEncainideStroke VolumeAdrenergic beta-AntagonistsAutonomic Nervous SystemConnexin 43Cardiotonic AgentsCardiac Imaging TechniquesVentricular Dysfunction, LeftTetralogy of FallotRetrospective StudiesPostoperative ComplicationsVentricular RemodelingEndocardiumAtrioventricular BlockPotassium Channels, Voltage-GatedQuinidineCardiac Output, LowProcainamideTachycardia, Ectopic AtrialMexiletineEpinephrineCalcium