Defibrillators, ImplantableDefibrillatorsElectric CountershockHeart-Assist DevicesPacemaker, ArtificialTachycardia, VentricularDeath, Sudden, CardiacHeart FailureArrhythmias, CardiacEquipment FailureVentricular FibrillationTreatment OutcomeElectrodes, ImplantedDevice RemovalEquipment SafetyEquipment DesignCardiac Pacing, ArtificialHeart ArrestElectric InjuriesCardiac Resynchronization TherapyCentral Nervous System Vascular MalformationsProstheses and ImplantsAlternative SplicingProsthesis ImplantationElectrocardiographyCardiac Resynchronization Therapy DevicesBalloon OcclusionImplantable NeurostimulatorsAnti-Arrhythmia AgentsEquipment Failure AnalysisEmbolization, TherapeuticFollow-Up StudiesAmiodaroneCavernous SinusCarotid-Cavernous Sinus FistulaCoronary SinusSyncopeTachycardiaSubclavian VeinCardiopulmonary ResuscitationInfusion Pumps, ImplantableRetrospective StudiesCerebral VeinsProspective StudiesTime FactorsDevice ApprovalForeign-Body MigrationCranial SinusesTelemetryArteriovenous FistulaPolyvinylsHeart BlockFeasibility StudiesAtrial FibrillationVentricular Dysfunction, LeftElectrophysiologic Techniques, CardiacElectrocardiography, AmbulatoryEquipment and SuppliesCatheterization, PeripheralVena Cava, SuperiorOut-of-Hospital Cardiac ArrestVenous CutdownStroke VolumeElectromagnetic PhenomenaCatheterizationCardiomyopathiesBrugada SyndromeRisk AssessmentDura MaterRemote Sensing TechnologyRecurrenceBradycardiaTachycardia, SupraventricularPrimary PreventionRisk FactorsHeart VentriclesCardiac CatheterizationPhlebographyEndocardiumBundle-Branch BlockDeath, SuddenCardiac ElectrophysiologyMonitoring, AmbulatoryProsthesis DesignElectrodesHeart Conduction SystemCardiography, ImpedanceSurvival RateCardiomyopathy, DilatedThoracotomyElectric Power SuppliesProsthesis FailureCerebral AngiographySurvival AnalysisMagnetsPericardiumVolunteersCost-Benefit AnalysisTherapy, Computer-AssistedMitral Valve Stenosis