Heart FailureHeartHeart RateMyocytes, CardiacCardiac Output, LowHeart Failure, SystolicHeart DiseasesMyocardiumCardiac OutputStroke VolumeHeart Failure, DiastolicHeart TransplantationVentricular Function, LeftCardiomyopathy, DilatedHemodynamicsCardiac Pacing, ArtificialVentricular Dysfunction, LeftMyocardial ContractionCardiomegalyNatriuretic Peptide, BrainVentricular RemodelingArrhythmias, CardiacEchocardiographyDeath, Sudden, CardiacHeart Defects, CongenitalTime FactorsCardiomyopathiesTreatment OutcomeCardiotonic AgentsChronic DiseaseCardiac Surgical ProceduresAdrenergic beta-AntagonistsTreatment FailureMyocardial InfarctionHeart Function TestsHeart VentriclesProspective StudiesFollow-Up StudiesHeart AtriaMyocardial IschemiaRisk FactorsFetal HeartPrognosisDisease Models, AnimalDogsCardiac CatheterizationElectrocardiographyAngiotensin-Converting Enzyme InhibitorsExercise TestHeart-Assist DevicesDiureticsBiological MarkersHeart ValvesSystoleRetrospective StudiesHospitalizationPredictive Value of TestsDiastolePropanolaminesAtrial Natriuretic FactorHeart ArrestBlood PressureCardiac Resynchronization TherapySeverity of Illness IndexVentricular DysfunctionVentricular PressureOxygen ConsumptionRisk AssessmentEchocardiography, DopplerExercise ToleranceFibrosisDigoxinHeart BlockPacemaker, ArtificialCardiac VolumeKidney Failure, ChronicRats, Sprague-DawleyCardiac TamponadeCardiovascular AgentsHypertrophy, Left VentricularCarbazolesCoronary DiseaseCardiac MyosinsMyocarditisProportional Hazards ModelsSurvival AnalysisModels, CardiovascularPulmonary Wedge PressureSurvival RatePatient ReadmissionNorepinephrineCalciumCohort StudiesSympathetic Nervous SystemDouble-Blind MethodSarcoplasmic Reticulum Calcium-Transporting ATPasesRats, WistarMineralocorticoid Receptor AntagonistsMetoprololAtrial Fibrillation