Sinoatrial NodeHeart RateSinoatrial BlockHeartTachycardia, Sinoatrial Nodal ReentryLymph NodesHeart AtriaBradycardiaAtrioventricular NodeBiological ClocksRabbitsAction PotentialsAtrial FunctionHeart Conduction SystemArrhythmia, SinusModels, CardiovascularHyperpolarization-Activated Cyclic Nucleotide-Gated ChannelsHeart BlockAutonomic Nervous SystemElectrocardiographyDogsVagus NerveCyclic Nucleotide-Gated Cation ChannelsSick Sinus SyndromeIsoproterenolAtrial Function, RightHeart Rate, FetalCalcium Channels, L-TypeCardiac Pacing, ArtificialMyocytes, CardiacHeart FailureElectrophysiologyTachycardia, SinusPotassium ChannelsMembrane PotentialsConnexinsCalcium Channels, T-TypeParasympathetic Nervous SystemMyocardial ContractionIon ChannelsConnexin 43Cardiotonic AgentsAdrenergic beta-AgonistsTime FactorsBlood PressureSympathetic Nervous SystemBenzazepinesAtropineArrhythmias, CardiacPatch-Clamp TechniquesAnti-Arrhythmia AgentsMyoblasts, CardiacHeart DiseasesLymph Node ExcisionMyocardiumGuinea PigsAminophyllinePacemaker, ArtificialMicroelectrodesDelayed Rectifier Potassium ChannelsHeart TransplantationElectrophysiological PhenomenaHeart Defects, CongenitalCardiac MyosinsHemodynamicsHeart ValvesCalciumSentinel Lymph Node BiopsySodium ChannelsTachycardiaSarcoplasmic ReticulumAcetylcholineSodium-Calcium ExchangerRyanodineTachycardia, SupraventricularFetal HeartComputer SimulationReceptors, Adrenergic, betaAging, PrematureCalcium SignalingAdrenergic beta-AntagonistsElectrophysiologic Techniques, CardiacNatriuretic Peptide, C-TypeHeart Function TestsMice, KnockoutIon Channel GatingRyanodine Receptor Calcium Release ChannelDose-Response Relationship, DrugElectrocardiography, AmbulatoryPapillary MusclesHeart VentriclesBaroreflexPhosphodiesterase 3 InhibitorsPropranololT-Box Domain ProteinsNorepinephrineCell SizeLymphatic MetastasisAtrial FibrillationCalcium Channel Blockers