Tachycardia, Sinoatrial Nodal ReentryTachycardia, Atrioventricular Nodal ReentryTachycardiaSinoatrial NodeTachycardia, SupraventricularTachycardia, VentricularCatheter AblationAtrioventricular NodeHeart Conduction SystemSinoatrial BlockElectrocardiographyTachycardia, SinusTachycardia, ParoxysmalTachycardia, Ectopic AtrialCryosurgeryTachycardia, Ectopic JunctionalTachycardia, ReciprocatingCardiac Pacing, ArtificialElectrophysiologic Techniques, CardiacPostural Orthostatic Tachycardia SyndromeAnti-Arrhythmia AgentsBundle of HisHeart AtriaHeart RateArrhythmias, CardiacBody Surface Potential MappingVentricular FibrillationHeart BlockWolff-Parkinson-White SyndromeElectrophysiologyBradycardiaAtrial FlutterHeart VentriclesDogsAction PotentialsFlecainideEndocardiumArrhythmia, SinusAtrial FunctionModels, CardiovascularDefibrillators, ImplantableAmiodaroneElectrocardiography, AmbulatoryProcainamide