Aortic Valve StenosisBalloon ValvuloplastyAortic ValvePulmonary Valve StenosisCatheterizationMitral Valve StenosisHeart Valve Prosthesis ImplantationAortic Valve InsufficiencyTricuspid Valve StenosisMitral ValveHeart Valve ProsthesisPulmonary ValveCardiac CatheterizationHeart Valve DiseasesRheumatic Heart DiseaseEchocardiographyCalcinosisBioprosthesisAtrial SeptumHemodynamicsFollow-Up StudiesTreatment OutcomeEchocardiography, DopplerSeverity of Illness IndexHypoplastic Left Heart SyndromeProsthesis DesignEchocardiography, TransesophagealCyanosisAngioplasty, BalloonBloodless Medical and Surgical ProceduresInfant, NewbornProspective StudiesCarotid StenosisTricuspid ValveMitral Valve InsufficiencyEchocardiography, Doppler, ColorAngiodysplasiaAortic Valve ProlapseBalloon OcclusionTime FactorsCoronary StenosisVentricular Function, LeftRetrospective StudiesBlood Flow VelocityRecurrenceVentricular Outflow ObstructionHeart VentriclesHeart Defects, CongenitalSpinal StenosisStroke VolumeTracheal StenosisAortaRisk FactorsConstriction, PathologicNoonan SyndromePredictive Value of TestsVentricular Dysfunction, LeftAngioplasty, Balloon, CoronaryBlood PressureObserver VariationRisk AssessmentPostoperative ComplicationsPulmonary Subvalvular StenosisMitral Valve AnnuloplastyEndocarditis, BacterialPyloric StenosisMitral Valve ProlapseDisease ProgressionAortic CoarctationReoperationIntra-Aortic Balloon PumpingPhonocardiographyTricuspid Valve InsufficiencyDiastoleDiscrete Subaortic StenosisHypertrophy, Left VentricularStentsCardiac Surgical ProceduresGastric BalloonEchocardiography, Three-DimensionalCardiac Valve AnnuloplastyVenous ValvesReproducibility of ResultsEndocarditisEndocardial FibroelastosisAortic AneurysmFetal TherapiesAortic Stenosis, SubvalvularHeart Septal Defects, VentricularCoronary AngiographyVenous InsufficiencyPregnancy Complications, CardiovascularTomography, X-Ray ComputedFeasibility Studies