Bundle-Branch BlockElectrocardiographyBundle of HisHeart Conduction SystemCardiac Pacing, ArtificialHeart BlockAjmalineCardiac Resynchronization TherapyVectorcardiographyPacemaker, ArtificialHeart SeptumArrhythmias, CardiacTachycardia, VentricularCardiomyopathy, DilatedAtrioventricular BlockHeart VentriclesElectrophysiologic Techniques, CardiacBrugada SyndromeTachycardia, ReciprocatingVentricular Dysfunction, LeftSyncopeDeath, Sudden, CardiacTachycardiaHeart FailureVentricular Function, LeftProcainamideEchocardiographyHeartVentricular Premature ComplexesCardiomyopathiesCatheter AblationMyocardial InfarctionVentricular DysfunctionPurkinje FibersEchocardiography, DopplerTreatment OutcomeStroke VolumeCardiac CatheterizationDefibrillators, ImplantableMyocytes, CardiacNerve BlockBody Surface Potential MappingAtrioventricular NodeVentricular FibrillationElectrocardiography, AmbulatorySyndromeTime FactorsProspective StudiesPredictive Value of TestsFollow-Up StudiesTachycardia, SupraventricularModels, CardiovascularMyocardial ContractionNAV1.5 Voltage-Gated Sodium ChannelExercise TestAnti-Arrhythmia AgentsPhonocardiographyCardiac Resynchronization Therapy DevicesThallium RadioisotopesZygapophyseal JointHeart Function TestsTomography, Emission-Computed, Single-PhotonWolff-Parkinson-White SyndromeRetrospective StudiesBradycardiaPrognosisMyocardiumTachycardia, Atrioventricular Nodal ReentryCardiac OutputVentricular Dysfunction, RightDogsCoronary AngiographyTetralogy of FallotHeart DiseasesVentricular RemodelingHeart RateSensitivity and SpecificityHeart AtriaIohexolCardiomyopathy, HypertrophicMitral Valve InsufficiencyTechnetium Tc 99m SestamibiSodium ChannelsHeart Valve Prosthesis ImplantationDipyridamoleHemodynamicsArrhythmogenic Right Ventricular DysplasiaMyocardial IschemiaThrombolytic TherapyCardiac Surgical ProceduresHeart Septal Defects, VentricularDobutamineElectrophysiologyCoronary DiseaseRisk FactorsHeart Valve ProsthesisEchocardiography, StressCoronary CirculationAortic Valve StenosisVentricular Function, Right