Heart FailureVentricular Function, LeftHeartVentricular Dysfunction, LeftStroke VolumeHeart RateVentricular Function, RightEchocardiographyHeart VentriclesMyocytes, CardiacVentricular FunctionMyocardiumMyocardial ContractionHemodynamicsCardiac Output, LowMyocardial InfarctionCardiomyopathy, DilatedHeart DiseasesCardiac OutputVentricular RemodelingTime FactorsSystoleHeart Function TestsCardiac Pacing, ArtificialCardiomyopathiesHeart Failure, SystolicTreatment OutcomeDiastoleElectrocardiographyCardiotonic AgentsHeart TransplantationNatriuretic Peptide, BrainHeart Failure, DiastolicCardiomegalyFollow-Up StudiesProspective StudiesVentricular Dysfunction, RightArrhythmias, CardiacCardiac CatheterizationMyocardial IschemiaAdrenergic beta-AntagonistsEchocardiography, DopplerHeart Defects, CongenitalHypertrophy, Left VentricularCardiac Surgical ProceduresChronic DiseaseBlood PressureExercise TestDogsVentricular PressureCardiac VolumeDeath, Sudden, CardiacHeart AtriaRadionuclide VentriculographyCoronary DiseaseCoronary CirculationPredictive Value of TestsPrognosisVentricular DysfunctionDisease Models, AnimalVasodilationTreatment FailureRisk FactorsGated Blood-Pool ImagingRetrospective StudiesAngiotensin-Converting Enzyme InhibitorsRadionuclide AngiographyHeart-Assist DevicesVasodilator AgentsSeverity of Illness IndexBiological MarkersPropanolaminesDobutamineCoronary VesselsExercise ToleranceDilatation, PathologicOxygen ConsumptionPacemaker, ArtificialFibrosisVascular ResistanceAtrial Natriuretic FactorMitral Valve InsufficiencyFetal HeartMyocarditisRats, Sprague-DawleyMyocardial Reperfusion InjuryRisk AssessmentDiureticsHeart ValvesCardiovascular AgentsMetoprololCardiac Resynchronization TherapyMagnetic Resonance Imaging, CineHeart BlockBlood Flow VelocityCoronary AngiographyArteriolesEchocardiography, Doppler, PulsedEchocardiography, Doppler, ColorCoronary Artery Bypass