SyncopeSyncope, VasovagalArrhythmias, CardiacADAM ProteinsSyndromeArrhythmia, SinusElectrocardiographyRhusTachycardia, VentricularLong QT SyndromeAnti-Arrhythmia AgentsElectrocardiography, AmbulatoryBradycardiaVentricular FibrillationDown SyndromeMetabolic Syndrome XDeath, Sudden, CardiacTachycardiaVentricular Premature ComplexesHeart RatePacemaker, ArtificialHeart Conduction SystemDefibrillators, ImplantableCardiac Pacing, ArtificialElectrophysiologic Techniques, CardiacRecurrenceCardiac Complexes, PrematureHeart BlockMidodrineNephrotic SyndromeMolecular WeightSick Sinus SyndromeAtrial FibrillationSjogren's SyndromeFollow-Up StudiesTime FactorsDisintegrinsNAV1.5 Voltage-Gated Sodium ChannelChromatography, GelTachycardia, SupraventricularPostureCatheter AblationTorsades de PointesProspective StudiesTreatment OutcomeHeart VentriclesHeartRisk FactorsDeath, SuddenWolff-Parkinson-White SyndromeAmyloid Precursor Protein SecretasesBrugada SyndromeAtrioventricular BlockTurner SyndromeAtrial FlutterFlecainideAutonomic Nervous SystemCardiac ElectrophysiologyHeart ArrestRetrospective StudiesAdrenergic beta-AntagonistsAbnormalities, MultipleMembrane ProteinsBlood PressureElectric CountershockMyelodysplastic SyndromesAmiodaroneDisopyramideCushing SyndromePhysicochemical PhenomenaMutationChemistry, PhysicalAcute Coronary SyndromeEther-A-Go-Go Potassium ChannelsCarotid SinusHeart AtriaBundle-Branch BlockDogsFludrocortisoneVentricular DysfunctionKCNQ1 Potassium ChannelUnconsciousnessPolycystic Ovary SyndromeMyocardiumAction PotentialsDizzinessPredictive Value of TestsMetalloendopeptidasesWilliams SyndromeMyocardial IschemiaPedigreeVagus NerveMyocardial InfarctionHemodynamicsCentrifugation, Density GradientEchocardiographyElectrophysiologyDiGeorge SyndromeHeart DiseasesModels, Cardiovascular