Membrane PotentialsAction PotentialsMembrane Potential, MitochondrialHeart Conduction SystemCell MembraneIntracellular MembranesMembranesPotassiumMembrane LipidsElectrocardiographyLong QT SyndromeElectrophysiologyPotassium ChannelsVentricular FunctionCalciumArrhythmias, CardiacMembranes, ArtificialPatch-Clamp TechniquesTorsades de PointesCell Membrane PermeabilityElectric ConductivityPotassium Channels, Voltage-GatedSodiumHeart VentriclesPotassium Channel BlockersGuinea PigsDogsAnti-Arrhythmia AgentsHeartIon ChannelsErythrocyte MembraneMitochondriaMembrane FluidityEther-A-Go-Go Potassium ChannelsDelayed Rectifier Potassium ChannelsPericardiumTime Factors4-AminopyridineRefractory Period, ElectrophysiologicalIon Channel GatingSotalolPurkinje FibersBasement MembraneRabbitsEndocardiumChloridesTetraethylammoniumMitochondrial MembranesElectric StimulationMyocytes, CardiacVentricular FibrillationMicroelectrodesKineticsVectorcardiographyValinomycinSodium ChannelsCells, CulturedKCNQ1 Potassium ChannelTetrodotoxinTetraethylammonium CompoundsNeuronsHydrogen-Ion ConcentrationCardiac Pacing, ArtificialModels, BiologicalModels, CardiovascularBrugada SyndromeMembrane Transport ProteinsMyocardiumElectrophysiologic Techniques, CardiacAdenosine TriphosphateCell LineQuinidineTachycardia, VentricularHeart RateBody Surface Potential MappingCalcium ChannelsFluorescent DyesBariumDose-Response Relationship, DrugCarbonyl Cyanide p-TrifluoromethoxyphenylhydrazoneBiological Transport, ActivePhenethylaminesLipid BilayersDeath, Sudden, CardiacMembrane GlycoproteinsProtein TransportTrityl CompoundsCesiumAtrial FunctionHeart AtriaSodium Channel BlockersMutationMicroscopy, ElectronCalcium Channels, L-TypeIon TransportRats, Sprague-DawleyOuabainCarbonyl Cyanide m-Chlorophenyl HydrazoneSynaptic MembranesCalcium Channel Blockers