Bundle-Branch BlockElectrocardiographyBundle of HisHeart Conduction SystemHeart BlockCardiac Pacing, ArtificialAjmalineCardiac Resynchronization TherapyVectorcardiographyPacemaker, ArtificialTachycardia, VentricularHeart SeptumAtrioventricular BlockCardiomyopathy, DilatedElectrophysiologic Techniques, CardiacArrhythmias, CardiacBrugada SyndromeHeart VentriclesTachycardia, ReciprocatingSyncopeTachycardiaVentricular Dysfunction, LeftProcainamideVentricular Premature ComplexesCatheter AblationHeart FailureVentricular Function, LeftPurkinje FibersEchocardiographyAtrioventricular NodeAnti-Arrhythmia AgentsDeath, Sudden, CardiacVentricular DysfunctionEchocardiography, DopplerCardiomyopathiesNerve BlockBody Surface Potential MappingDefibrillators, ImplantableTreatment OutcomeVentricular FibrillationMyocardial InfarctionElectrocardiography, AmbulatorySyndromeStroke VolumeTime FactorsTachycardia, SupraventricularProspective StudiesPredictive Value of TestsFollow-Up StudiesHeartNAV1.5 Voltage-Gated Sodium ChannelBradycardiaPhonocardiographyWolff-Parkinson-White SyndromeZygapophyseal JointCardiac CatheterizationExercise TestThallium RadioisotopesModels, CardiovascularTachycardia, Atrioventricular Nodal ReentryCardiac Resynchronization Therapy DevicesLong QT SyndromeTomography, Emission-Computed, Single-PhotonPrognosisDogsRetrospective StudiesVentricular Dysfunction, RightTetralogy of FallotMyocardial ContractionHeart Function TestsHeart RateIohexolCoronary AngiographySensitivity and SpecificityTorsades de PointesHeart AtriaSodium ChannelsTechnetium Tc 99m SestamibiElectrophysiologyMitral Valve InsufficiencyDipyridamoleArrhythmogenic Right Ventricular DysplasiaMyocardiumThrombolytic TherapyCardiomyopathy, HypertrophicHeart Valve Prosthesis ImplantationVentricular RemodelingHeart Septal Defects, VentricularVerapamilTachycardia, ParoxysmalDobutamineAction PotentialsSignal Processing, Computer-AssistedHeart Valve ProsthesisEchocardiography, StressVentricular Function, RightMyocardial IschemiaCoronary DiseaseFalse Positive ReactionsRisk Factors