Tachycardia, VentricularTachycardiaElectrocardiographyTachycardia, SupraventricularCatheter AblationVentricular FibrillationAnti-Arrhythmia AgentsTachycardia, Atrioventricular Nodal ReentryTachycardia, SinusArrhythmias, CardiacHeart Conduction SystemElectrophysiologic Techniques, CardiacCardiac Pacing, ArtificialTachycardia, ParoxysmalBody Surface Potential MappingDefibrillators, ImplantableVentricular Premature ComplexesTachycardia, Ectopic AtrialEndocardiumAmiodaroneEpicardial MappingDeath, Sudden, CardiacElectrocardiography, AmbulatoryCardiac Complexes, PrematureHeart VentriclesBundle-Branch BlockProcainamideElectric CountershockFlecainideSyncopeArrhythmogenic Right Ventricular DysplasiaTachycardia, Ectopic JunctionalBundle of HisElectrophysiologyCardiomyopathiesHeart RatePericardiumPostural Orthostatic Tachycardia SyndromeSotalolFollow-Up StudiesCalsequestrinTachycardia, ReciprocatingCryosurgeryMyocardial InfarctionTachycardia, Sinoatrial Nodal ReentryMexiletineCicatrixAtrioventricular NodeTreatment OutcomeDeath, SuddenWolff-Parkinson-White SyndromeHeart BlockRecurrenceLong QT SyndromeBrugada SyndromeTorsades de PointesRyanodine Receptor Calcium Release ChannelCardiomyopathy, DilatedHeart ArrestPropafenoneAccelerated Idioventricular RhythmDogsVerapamilTime FactorsPurkinje FibersHeartCardiac ElectrophysiologyAtrial FlutterEchocardiographyCardiomyopathy, HypertrophicPre-Excitation SyndromesAndersen SyndromeSignal Processing, Computer-AssistedNAV1.5 Voltage-Gated Sodium ChannelRefractory Period, ElectrophysiologicalPacemaker, ArtificialAdrenergic beta-AntagonistsTetralogy of FallotVentricular DysfunctionVentricular SeptumStroke VolumeProspective StudiesAction PotentialsPredictive Value of TestsMyocardial IschemiaRetrospective StudiesCatecholaminesBradycardiaDisopyramideCardiac CatheterizationVentricular Dysfunction, LeftHeart AneurysmHeart AtriaMyocardiumAtrioventricular BlockAtrial FibrillationDigitalis GlycosidesCardiac Imaging TechniquesExercise TestPrenylamine