Heart BlockHeartAdams-Stokes SyndromeHeart RatePacemaker, ArtificialAtrioventricular NodeRNA, Small CytoplasmicBradycardiaElectrocardiographyAtrioventricular BlockAntibodies, AntinuclearHeart Defects, CongenitalFetal HeartFetal DiseasesCardiac Pacing, ArtificialHeart FailureHeart Conduction SystemBundle of HisHeart Rate, FetalHeart DiseasesBundle-Branch BlockMaternal-Fetal ExchangeRibonucleoproteinsNerve BlockSteroids, FluorinatedKearns-Sayre SyndromeMyocardiumEndocardial FibroelastosisHeart TransplantationSinoatrial NodeSyncopeHeart AtriaEchocardiographyHeart SeptumPregnancyHeart Septal Defects, VentricularCardiomyopathiesTime FactorsInfant, NewbornLupus Erythematosus, CutaneousMagnetocardiographyFollow-Up StudiesAutoantibodiesAutoantigensTreatment OutcomePregnancy ComplicationsLupus Erythematosus, SystemicArrhythmias, CardiacHydrops FetalisProspective StudiesElectrocardiography, AmbulatoryHeart ValvesAutoimmune DiseasesMyocardial InfarctionRisk FactorsCardiac CatheterizationCardiomyopathy, DilatedUltrasonography, PrenatalMyocytes, CardiacImmunity, Maternally-AcquiredHemodynamicsCollagen DiseasesArrhythmia, SinusRetrospective StudiesBetamethasoneMyocarditisPrenatal DiagnosisHeart AuscultationTransposition of Great VesselsSick Sinus SyndromeMothersHeart Valve ProsthesisPrognosisMetoprololCardiomyopathy, Hypertrophic