Atrial FlutterCatheter AblationAtrial FibrillationTricuspid ValveElectrocardiographyHeart AtriaPropafenoneAnti-Arrhythmia AgentsPericarditisElectrophysiologic Techniques, CardiacHeart BlockProcainamideElectric CountershockCardiac Pacing, ArtificialHeart Conduction SystemBody Surface Potential MappingAtrial Function, RightTachycardia, SupraventricularVena Cava, InferiorDisopyramideFlecainideAtrial FunctionAmiodaroneTachycardiaRefractory Period, ElectrophysiologicalAtrial Premature ComplexesTachycardia, Ectopic AtrialTachycardia, ParoxysmalAtrial Function, LeftHydrops FetalisCryosurgeryPulmonary VeinsTreatment OutcomeElectrophysiologyFollow-Up StudiesCoronary SinusRecurrenceFluoroscopyArrhythmias, CardiacAtrioventricular NodeCardiac CathetersEchocardiography, TransesophagealButylscopolammonium BromideSick Sinus SyndromeTachycardia, Sinoatrial Nodal ReentryDogsVentricular Function, LeftFetal DiseasesEchocardiographyElectrocardiography, AmbulatoryProspective StudiesVenae Cavae