Atrioventricular BlockHeart BlockBundle-Branch BlockElectrocardiographyPacemaker, ArtificialBundle of HisCardiac Pacing, ArtificialHeart Conduction SystemAtrioventricular NodeBradycardiaRhododendronSyncopeTorsades de PointesTachycardia, Atrioventricular Nodal ReentryNeriumInferior Wall Myocardial InfarctionCatheter AblationArrhythmias, CardiacElectrocardiography, AmbulatoryEchocardiographyHeart VentriclesVectorcardiographyCardiomyopathiesAjmalineTreatment OutcomeRadionuclide VentriculographyElectrophysiologic Techniques, CardiacHeart SeptumMyocarditisTachycardia, VentricularCardiac Resynchronization TherapyCardiomyopathy, DilatedDogsFollow-Up StudiesHeart RateTachycardiaVentricular Dysfunction, LeftNerve BlockBrugada SyndromeTime FactorsTachycardia, ReciprocatingRetrospective StudiesPurkinje FibersAnti-Arrhythmia AgentsTachycardia, SupraventricularVentricular Function, LeftProcainamideHeart FailureVentricular Premature ComplexesMagnetocardiographyCardiac CatheterizationEchocardiography, DopplerMyocardial InfarctionSick Sinus SyndromeDeath, Sudden, CardiacAdams-Stokes SyndromeNAV1.5 Voltage-Gated Sodium ChannelProspective StudiesWolff-Parkinson-White SyndromeVentricular DysfunctionHeartExercise TestHeart Septal Defects, VentricularDisopyramideBody Surface Potential MappingDefibrillators, ImplantablePredictive Value of TestsCardiomyopathy, HypertrophicSyndromeStroke VolumeVentricular FibrillationHeart AtriaPrognosisHeart Valve Prosthesis ImplantationZygapophyseal JointPhonocardiographyThallium RadioisotopesFetal DiseasesAtrial FibrillationCoronary AngiographyCardiac Resynchronization Therapy DevicesTomography, Emission-Computed, Single-PhotonModels, CardiovascularHydrops FetalisElectrophysiologyMyocardial ContractionMyocardiumVentricular Dysfunction, RightAortic Valve StenosisHeart Valve ProsthesisTetralogy of FallotFetal TherapiesIncidenceHeart Function TestsRisk FactorsCardiomyopathy, RestrictiveIohexolArrhythmia, SinusHemodynamicsAdenosine