Tachycardia, SupraventricularTachycardiaTachycardia, ParoxysmalTachycardia, VentricularTachycardia, Atrioventricular Nodal ReentryTachycardia, Sinoatrial Nodal ReentryElectrocardiographyWolff-Parkinson-White SyndromeBundle-Branch BlockTachycardia, SinusTachycardia, Ectopic AtrialCatheter AblationTachycardia, Ectopic JunctionalAnti-Arrhythmia AgentsAtrioventricular NodeArrhythmias, CardiacHeart Conduction SystemAtrial Premature ComplexesCardiac Pacing, ArtificialElectrophysiologic Techniques, CardiacBundle of HisHydrops FetalisFlecainideAtrial FlutterElectrocardiography, AmbulatoryAmiodaroneDigoxinPostural Orthostatic Tachycardia SyndromeCardiac Complexes, PrematurePre-Excitation SyndromesAccessory Atrioventricular BundleAtrial FibrillationHeart RateTachycardia, ReciprocatingFetal DiseasesBody Surface Potential MappingHeart AtriaDefibrillators, ImplantableVentricular FibrillationVentricular Premature ComplexesElectric CountershockSotalolHeart BlockElectrocoagulationProcainamideTreatment OutcomeFollow-Up StudiesAtrioventricular BlockSyncopePropafenoneVerapamilHeart VentriclesElectrophysiologyHeart Rate, FetalSinoatrial NodeRecurrenceBradycardiaPacemaker, ArtificialAntazolineTime FactorsRetrospective StudiesDeath, Sudden, CardiacEchocardiographyDisopyramideHeart Defects, CongenitalHydroxyzineFinancial AuditDogsAdrenergic beta-AntagonistsCardiomyopathiesAdenosineCardiomyopathy, DilatedHeartCryosurgeryInfant, NewbornTricuspid AtresiaProspective StudiesCardiac Surgical ProceduresAtrial FunctionEndocardiumFetal DistressCardiac CatheterizationHeterotaxy SyndromeHemodynamicsPostoperative ComplicationsLavandulaRefractory Period, ElectrophysiologicalArrhythmia, SinusEbstein Anomaly