Heart Failure, SystolicChemoreceptor CellsHeart FailureCarotid BodyHeartRespirationHeart RateHeart Failure, DiastolicCardiac Output, LowSodium CyanideHypercapniaStroke VolumeNatriuretic Peptide, BrainCarbon DioxideAnoxiaHypersensitivity, DelayedVentricular Dysfunction, LeftSystoleAlmitrineAdrenergic beta-AntagonistsChronic DiseaseDoxapramPhrenic NerveVentricular Function, LeftEchocardiography, DopplerApneaPulmonary VentilationOxygenRespiratory MechanicsBlood Circulation TimeTime FactorsReflexHospitalizationDiastoleCarotid SinusTreatment OutcomeHeart TransplantationDrug HypersensitivityExercise TestTidal VolumeHyperventilationDenervationVentricular RemodelingAdrenergic NeuronsSolitary NucleusEchocardiographyFollow-Up StudiesHyperoxiaProspective StudiesHemodynamicsVagotomyPrognosisMedulla OblongataBlood PressureSympathetic Nervous SystemPropanolaminesRespiratory CenterBiological MarkersSeverity of Illness IndexAngiotensin-Converting Enzyme InhibitorsMineralocorticoid Receptor AntagonistsSpironolactonePeripheral Nervous SystemCardiac Pacing, ArtificialDiureticsDigoxinMyocardial ContractionCardiovascular AgentsMyocardiumHeart DiseasesPredictive Value of TestsRisk FactorsPhosphodiesterase 5 InhibitorsCardiomyopathy, DilatedPressoreceptorsRespiratory Physiological PhenomenaExercise ToleranceProportional Hazards ModelsKaplan-Meier EstimateTreatment FailurePulmonary Wedge PressureRats, Sprague-DawleyHeart VentriclesCardiac Resynchronization TherapyRisk AssessmentOxygen ConsumptionRetrospective StudiesOutpatientsElectrocardiographyHeart Defects, CongenitalPlethysmography, Whole BodyCardiotonic AgentsSurvival RateCatsDouble-Blind MethodVentricular Function, RightSurvival AnalysisBrain StemBlood Gas AnalysisBaroreflex