AngiocardiographyEchocardiographySodium Pertechnetate Tc 99mDextrocardiaIridiumRadionuclide GeneratorsTechnetiumEchocardiography, TransesophagealRadionuclide AngiographyEchocardiography, Three-DimensionalEchocardiography, DopplerGated Blood-Pool ImagingEchocardiography, StressVentriculography, First-PassCineangiographyHeart VentriclesEchocardiography, Doppler, ColorHeart Defects, CongenitalCardiac CatheterizationHeartStroke VolumeEchocardiography, Doppler, PulsedDobutamineCoronary DiseaseVentricular Function, LeftVentricular Dysfunction, LeftMitral ValveMitral Valve InsufficiencyHeart DiseasesHeart AtriaHeart Septal Defects, AtrialHeart Valve DiseasesDiastoleObserver VariationPredictive Value of TestsSystoleHeart NeoplasmsElectrocardiographyExercise TestMyocardial ContractionSensitivity and SpecificityAortic ValveCardiotonic AgentsFetal HeartEchocardiography, Four-DimensionalContrast MediaHypertrophy, Left VentricularProspective StudiesFeasibility StudiesHeart SeptumHemodynamicsBlood Flow VelocityCoronary CirculationHeart Valve ProsthesisTricuspid Valve InsufficiencyAortic Valve InsufficiencyTricuspid ValveAortic Valve StenosisReproducibility of ResultsMitral Valve ProlapseCardiomyopathies