Heart FailureDiastoleVentricular Function, LeftHeartVentricular Dysfunction, LeftStroke VolumeHeart RateVentricular Function, RightEchocardiographyHeart VentriclesMyocardial ContractionVentricular FunctionMyocardiumMyocytes, CardiacSystoleHemodynamicsCardiac Output, LowMyocardial InfarctionHeart DiseasesCardiac OutputCardiomyopathy, DilatedEchocardiography, DopplerVentricular RemodelingCardiac Pacing, ArtificialTime FactorsElectrocardiographyCardiomyopathiesHeart Function TestsHeart Failure, SystolicCost-Benefit AnalysisDogsTreatment OutcomeVentricular Dysfunction, RightCardiac CatheterizationArrhythmias, CardiacCardiomegalyHeart TransplantationCardiac VolumeNatriuretic Peptide, BrainHeart Failure, DiastolicProspective StudiesVentricular PressureMyocardial IschemiaFollow-Up StudiesBlood PressureHypertrophy, Left VentricularCoronary CirculationCardiac Surgical ProceduresAdrenergic beta-AntagonistsHeart AtriaHeart Defects, CongenitalChronic DiseaseExercise TestCoronary DiseaseDeath, Sudden, CardiacPredictive Value of TestsRadionuclide VentriculographyMitral ValvePrognosisVentricular DysfunctionBlood Flow VelocityDisease Models, AnimalEchocardiography, Doppler, PulsedEchocardiography, Doppler, ColorTreatment FailureModels, CardiovascularRisk FactorsGated Blood-Pool ImagingFetal HeartHeart-Assist DevicesMitral Valve InsufficiencyAtrial Function, LeftRetrospective StudiesMagnetic Resonance Imaging, CineDobutamineRadionuclide AngiographyAngiotensin-Converting Enzyme InhibitorsSeverity of Illness IndexPropanolaminesOxygen ConsumptionBiological MarkersPhonocardiographyHeart SeptumExercise ToleranceCoronary VesselsPacemaker, ArtificialEndocardiumPulmonary Wedge PressureCineangiographyAtrial Natriuretic FactorVascular ResistanceFibrosisAngiocardiographyMyocarditisCoronary AngiographyDiureticsHeart ValvesMyocardial Reperfusion InjuryCardiac Resynchronization TherapyHeart Block