Myocytes, CardiacHeart FailureHeartHeart RateHeart DiseasesHeart TransplantationHeart Defects, CongenitalFetal HeartHeart ValvesHeart AtriaHeart BlockMyocardiumHeart Arrest, InducedHeart Function TestsMyocardial ContractionMyocardial IschemiaCoronary DiseaseHemodynamicsCardiac Output, LowVentricular Function, LeftTime FactorsHeart, ArtificialHeart Failure, SystolicPerfusionCardiomyopathy, DilatedCardiomegalyMyocardial InfarctionHeart InjuriesHeart Rate, FetalHeart SeptumCardiotonic AgentsRheumatic Heart DiseaseStroke VolumeCardiomyopathiesEchocardiographyMyocardial Reperfusion InjuryHeart ArrestRisk FactorsHeart Valve ProsthesisVentricular Dysfunction, LeftAdrenergic beta-AntagonistsHeart Failure, DiastolicAmerican Heart AssociationVentricular RemodelingDogsProspective StudiesOxygen ConsumptionFollow-Up StudiesAutonomic Nervous SystemCardiac Pacing, ArtificialHeart Septal DefectsHypoplastic Left Heart SyndromeHeart NeoplasmsRats, Sprague-DawleyChronic DiseaseNational Heart, Lung, and Blood Institute (U.S.)Natriuretic Peptide, BrainDisease Models, AnimalRats, WistarVentricular PressureTreatment OutcomeExercise TestSympathetic Nervous SystemModels, CardiovascularSystoleEndocardiumDiastoleIsoproterenolPropanolaminesHeart Septal Defects, VentricularBiological MarkersIschemic Preconditioning, MyocardialRabbitsMyocarditisHeart-Assist DevicesCalciumElectrocardiography, AmbulatoryCardiovascular DiseasesNorepinephrinePrognosisPredictive Value of TestsCohort StudiesAnti-Arrhythmia AgentsRisk AssessmentRetrospective StudiesRNA, MessengerHypertrophy, Left VentricularMyocardial ReperfusionHeart Valve Prosthesis ImplantationHeart Septal Defects, AtrialVentricular DysfunctionDose-Response Relationship, DrugCardiac Surgical ProceduresAge FactorsBaroreflexFibrosisVascular ResistanceCardiac CatheterizationEchocardiography, DopplerSinoatrial Node