Exercise TestEchocardiographyEchocardiography, TransesophagealEchocardiography, DopplerEchocardiography, Three-DimensionalExercise ToleranceExerciseEchocardiography, StressExercise TherapyEchocardiography, Doppler, ColorPhysical ExertionOxygen ConsumptionEchocardiography, Doppler, PulsedElectrocardiographyHeart RateDobutamineVentricular Function, LeftPhysical EnduranceVentricular Dysfunction, LeftStroke VolumeAnaerobic ThresholdHeart VentriclesPredictive Value of TestsHemodynamicsPhysical FitnessAsthma, Exercise-InducedMitral ValveHeart DiseasesBicyclingCoronary DiseasePulmonary Gas ExchangeTime FactorsHeart FailureProspective StudiesSystoleDiastoleMitral Valve InsufficiencyHeartAngina PectorisCardiac CatheterizationSensitivity and SpecificityBlood PressureMuscle, SkeletalMyocardial IschemiaFollow-Up StudiesRestMyocardial ContractionHeart AtriaHeart Defects, CongenitalHeart Septal Defects, AtrialFeasibility StudiesCoronary CirculationLactic AcidMyocardial InfarctionBlood Flow VelocityReproducibility of ResultsHeart Valve DiseasesObserver VariationCoronary AngiographyDyspneaCardiac OutputErgometrySportsDipyridamoleTreatment OutcomeHeart NeoplasmsCardiotonic AgentsRunningRespiratory Function TestsAortic ValvePrognosisHeart Function TestsHypertrophy, Left VentricularAortic Valve StenosisFetal HeartEchocardiography, Four-DimensionalContrast MediaHeart SeptumAnalysis of VarianceHeart Valve ProsthesisSeverity of Illness IndexRespirationCardiomyopathy, DilatedTricuspid Valve InsufficiencyAortic Valve InsufficiencyCardiovascular Physiological PhenomenaTomography, Emission-Computed, Single-PhotonTricuspid ValvePhysical Education and TrainingCardiac VolumeVentricular RemodelingMitral Valve StenosisCardiomyopathiesRisk FactorsOxygenHypertension, PulmonaryMitral Valve ProlapseVentricular Function, RightAtrial Function, LeftAdrenergic beta-Antagonists