Heart Conduction SystemCoronary SinusCoronary VesselsAtrioventricular NodeHeartBundle of HisNeural ConductionCoronary AngiographyCoronary CirculationHeart BlockCoronary Artery DiseaseSinus of ValsalvaPurkinje FibersElectrocardiographyHeart AtriaSinoatrial NodeCardiac Pacing, ArtificialHeart RateMyocardiumAngioplasty, Balloon, CoronaryCoronary StenosisHeart VentriclesCoronary DiseaseConnexinsCoronary Artery BypassCranial SinusesMaxillary SinusArrhythmias, CardiacAtrioventricular BlockDogsParanasal SinusesPacemaker, ArtificialCatheter AblationWolff-Parkinson-White SyndromeCavernous SinusCoronary Vessel AnomaliesHeart FailureVena Cava, SuperiorCardiac CatheterizationCoronary AneurysmElectrophysiologic Techniques, CardiacCarotid SinusHeart Defects, CongenitalTime FactorsCoronary VasospasmHeart DiseasesAtrial FibrillationVentricular FunctionTachycardia, Atrioventricular Nodal ReentryT-Box Domain ProteinsFrontal SinusParanasal Sinus DiseasesAtrial FlutterCardiac ElectrophysiologyMyocardial InfarctionSphenoid SinusHeart SeptumHeart Arrest, InducedTreatment OutcomeHeterotaxy SyndromeElectrophysiologyModels, CardiovascularRefractory Period, ElectrophysiologicalMyocardial IschemiaAction PotentialsAtrial FunctionHemodynamicsTachycardiaMyocardial ContractionMyocytes, CardiacDextrocardiaSick Sinus SyndromeSp4 Transcription FactorConnexin 43Coronary ThrombosisAnti-Arrhythmia AgentsFollow-Up StudiesAcetylthiocholineBundle-Branch BlockTachycardia, Sinoatrial Nodal ReentryCardiomyopathiesHeart TransplantationTachycardia, SupraventricularSinus Thrombosis, IntracranialProspective StudiesCardiomyopathy, DilatedGene Expression Regulation, DevelopmentalPericardiumRisk FactorsEchocardiographyBody Surface Potential MappingEthmoid SinusCoronary RestenosisElectrodes, ImplantedGATA6 Transcription FactorCoronary OcclusionFetal HeartTachycardia, ParoxysmalNAV1.5 Voltage-Gated Sodium ChannelBradycardia