Heart RateHeartBlood PressureSympathetic Nervous SystemAdrenergic beta-AntagonistsSciatic NervePeripheral NervesNerve FibersOptic NerveHeart Rate, FetalHeart FailureAutonomic Nervous SystemNerve RegenerationHeart DiseasesNerve BlockHeart TransplantationNerve EndingsHemodynamicsHeart Defects, CongenitalSural NerveMedian NerveFacial NerveNerve CrushPeripheral Nerve InjuriesTibial NerveUlnar NerveFetal HeartFemoral NerveBaroreflexSpinal NervesHeart AtriaElectrocardiography, AmbulatoryTrigeminal NerveParasympathetic Nervous SystemNerve Growth FactorElectrocardiographyNerve Growth FactorsPhrenic NerveHeart ValvesDogsExercise TestRadial NerveMyocardial ContractionCranial NervesSpinal Nerve RootsHeart BlockMyocardiumNerve Compression SyndromesTime FactorsOxygen ConsumptionOphthalmic NerveReflexRespirationHeart Function TestsNerve TissueAtropinePropranololBradycardiaTelemetryPressoreceptorsMandibular NerveElectric StimulationRats, Sprague-DawleySplanchnic NervesStroke VolumeCardiovascular Physiological PhenomenaMyocardial IschemiaVentricular Function, LeftTachycardiaCochlear NerveCardiovascular SystemPhysical ExertionExerciseGlossopharyngeal NerveNeural ConductionCoronary DiseaseRestPropanolaminesCardiac OutputDenervationRats, WistarCardiotonic AgentsSinoatrial NodeOptic Nerve InjuriesNerve Fibers, MyelinatedHeart Arrest, InducedOptic Nerve DiseasesAutonomic Nervous System DiseasesDose-Response Relationship, DrugThoracic NervesNorepinephrineProspective Studies