Pulmonary VeinsVena Cava, SuperiorSuperior Vena Cava SyndromeVena Cava, InferiorCatheter AblationAtrial FibrillationHeart AtriaVeinsPulmonary Veno-Occlusive DiseaseVenae CavaeBrachiocephalic VeinsAzygos VeinElectrophysiologic Techniques, CardiacPhlebographyJugular VeinsVena Cava FiltersVascular MalformationsSaphenous VeinCoronary SinusCryosurgeryPortal VeinHeart Conduction SystemFemoral VeinTreatment OutcomeBody Surface Potential MappingVaricose VeinsCatheterization, Central VenousConstriction, PathologicSubclavian VeinTachycardia, Ectopic AtrialTomography, X-Ray ComputedHepatic VeinsScimitar SyndromeEchocardiography, TransesophagealCardiac CathetersAtrial SeptumRenal VeinsFluoroscopyCatheterizationIliac VeinDogsElectrocardiographyHeart Septal Defects, AtrialHeart Defects, CongenitalPulmonary ArteryHeart Bypass, RightRecurrenceMesenteric VeinsCardiac Pacing, ArtificialFollow-Up StudiesAtrial FunctionSinoatrial NodeMediastinal DiseasesAtrial FlutterCardiac Complexes, PrematureMediastinal NeoplasmsTachycardia, ParoxysmalIncidental FindingsEchocardiographyImaging, Three-DimensionalCardiac Surgical ProceduresVascular NeoplasmsPericardiumPacemaker, ArtificialTime FactorsPulmonary CirculationUmbilical VeinsHeart NeoplasmsSurgery, Computer-AssistedAnti-Arrhythmia AgentsDevice RemovalVascular DiseasesVenous ThrombosisVenous PressureCardiac CatheterizationAutonomic DenervationAtrial Premature ComplexesSuperior ColliculiBlood Flow VelocityEquipment DesignPopliteal VeinCardiovascular AbnormalitiesAtrial AppendageProspective StudiesBreath HoldingAnastomosis, SurgicalMultidetector Computed TomographyChylothoraxAtrial Function, LeftAngiographyFeasibility StudiesPulmonary EmbolismStentsTachycardia, SupraventricularFistulaElectrocardiography, AmbulatorySplenic VeinRetrospective StudiesCentral Venous CathetersBudd-Chiari Syndrome