Heart Conduction SystemElectrocardiographyHeart BlockArrhythmias, CardiacNeural ConductionAtrioventricular BlockBundle-Branch BlockMyotonic DystrophyHeartCardiac Pacing, ArtificialAtrioventricular NodeMyocytes, CardiacNAV1.5 Voltage-Gated Sodium ChannelAdams-Stokes SyndromeHeart DiseasesBradycardiaHeart AtriaElectrophysiologic Techniques, CardiacPacemaker, ArtificialMyocardiumCardiac ElectrophysiologyDeath, Sudden, CardiacBundle of HisAction PotentialsDogsPurkinje FibersBrugada SyndromeCardiac OutputHeart VentriclesSodium ChannelsTime FactorsConnexinsHeart RateAtrial FibrillationSinus Arrest, CardiacDisease Models, AnimalSinoatrial NodeModels, CardiovascularConnexin 43Cardiac Surgical ProceduresAnti-Arrhythmia AgentsFollow-Up StudiesKearns-Sayre SyndromeLong QT SyndromeSp4 Transcription FactorCardiomyopathy, DilatedMyocardial InfarctionElectrophysiologyEchocardiographyCardiomegalyCardiac CatheterizationMyocardial ContractionGap JunctionsMice, TransgenicCardiomyopathiesMutationVectorcardiographyT-Box Domain ProteinsMuscle ProteinsPhenotypeCardiac TamponadeElectrocardiography, AmbulatoryHeart FailureHeart ArrestTachycardiaSyndromeSignal Processing, Computer-AssistedProspective StudiesGene Expression Regulation, DevelopmentalPredictive Value of TestsVentricular FibrillationMuscular Dystrophy, Emery-DreifussHemodynamicsMyocardial IschemiaTachycardia, VentricularPedigreeVentricular Function, LeftBlood PressureVentricular FunctionBody Surface Potential MappingLamin Type ATreatment OutcomeCardiac Complexes, PrematureMice, KnockoutHeart Defects, CongenitalVentricular Dysfunction, LeftStroke VolumeLac OperonCardiac VolumeMyoblasts, CardiacExercise TestCatheter AblationTroponin IWolff-Parkinson-White SyndromeRetrospective StudiesRisk FactorsCardiac MyosinsSyncopeCoronary DiseaseCardiac Imaging Techniques