Defibrillators, ImplantableDefibrillatorsElectric CountershockPacemaker, ArtificialEquipment FailureTachycardia, VentricularVentricular FibrillationDeath, Sudden, CardiacArrhythmias, CardiacElectrodes, ImplantedDevice RemovalCardiac Pacing, ArtificialHeart ArrestEquipment SafetyEquipment DesignCardiac Resynchronization TherapyElectrocardiographyElectric InjuriesTreatment OutcomeCentral Nervous System Vascular MalformationsCardiac Resynchronization Therapy DevicesHeart FailureProsthesis ImplantationAnti-Arrhythmia AgentsBalloon OcclusionImplantable NeurostimulatorsProstheses and ImplantsFollow-Up StudiesMyocytes, CardiacAmiodaroneEmbolization, TherapeuticEquipment Failure AnalysisCavernous SinusCardiopulmonary ResuscitationSyncopeManuals as TopicCoronary SinusCarotid-Cavernous Sinus FistulaTachycardiaTime FactorsSubclavian VeinProspective StudiesRetrospective StudiesVentricular Dysfunction, LeftInfusion Pumps, ImplantableOut-of-Hospital Cardiac ArrestCardiac OutputCardiomyopathiesHeart VentriclesCerebral VeinsHeart BlockCardiac CatheterizationHeartStroke VolumeArteriovenous FistulaAtrial FibrillationElectrophysiologic Techniques, CardiacCranial SinusesTelemetryElectrocardiography, AmbulatoryPolyvinylsFeasibility StudiesForeign-Body MigrationHeart DiseasesCardiac ElectrophysiologyVena Cava, SuperiorHeart Conduction SystemRisk AssessmentRisk FactorsCardiac Surgical ProceduresBradycardiaCardiomyopathy, DilatedCatheterization, PeripheralBrugada SyndromeVenous CutdownEndocardiumDeath, SuddenElectromagnetic PhenomenaCatheterizationRecurrenceBundle-Branch BlockDura MaterTachycardia, SupraventricularEchocardiographyPericardiumCardiography, ImpedancePrimary PreventionHeart AtriaSurvival RateHeart-Assist DevicesPhlebographyCardiac Output, LowRemote Sensing TechnologySurvival AnalysisMyocardial InfarctionThoracotomyEmergency Medical ServicesHeart RateMonitoring, AmbulatoryVolunteers