Heart RateHeartHeart Rate, FetalHeart FailureAutonomic Nervous SystemBlood PressureHeart DiseasesHeart TransplantationHeart Defects, CongenitalHemodynamicsFetal HeartSympathetic Nervous SystemElectrocardiography, AmbulatoryBaroreflexHeart AtriaElectrocardiographyAdrenergic beta-AntagonistsHeart ValvesExercise TestMyocardial ContractionHeart BlockMyocardiumTime FactorsOxygen ConsumptionHeart Function TestsParasympathetic Nervous SystemTelemetryDogsBradycardiaPropranololStroke VolumeRespirationMyocardial IschemiaVentricular Function, LeftCardiovascular Physiological PhenomenaTachycardiaPhysical ExertionCoronary DiseaseExerciseCardiovascular SystemAtropineRestPressoreceptorsPropanolaminesCardiac OutputCardiotonic AgentsHeart Arrest, InducedNorepinephrineSinoatrial NodeEchocardiographyReflexAutonomic Nervous System DiseasesMyocardial InfarctionMyocytes, CardiacArrhythmia, SinusCardiac Output, LowProspective StudiesCardiac Pacing, ArtificialPostureMetoprololIsoproterenolRisk FactorsSupine PositionModels, CardiovascularDouble-Blind MethodDose-Response Relationship, DrugSystoleSignal Processing, Computer-AssistedEpinephrineCardiomyopathy, DilatedBody TemperatureRats, Sprague-DawleyDiastoleVentricular Dysfunction, LeftReference ValuesRats, WistarRegional Blood FlowArrhythmias, CardiacCircadian RhythmTilt-Table TestAtenololHypotensionCardiomegalyFetal MonitoringCatecholaminesAnti-Arrhythmia AgentsFollow-Up StudiesPhenylephrineMyocardial Reperfusion InjuryAnesthesiaCardiomyopathiesHeart Failure, SystolicTreatment OutcomeCross-Over StudiesPredictive Value of TestsAdrenergic beta-AgonistsHeart ArrestMonitoring, PhysiologicHypertensionConsciousness