Defibrillators, ImplantableDefibrillatorsElectric CountershockVentricular FibrillationDeath, Sudden, CardiacTachycardia, VentricularArrhythmias, CardiacHeart ArrestEquipment FailureMyocytes, CardiacPacemaker, ArtificialCardiac Resynchronization TherapyCardiac Pacing, ArtificialCardiopulmonary ResuscitationElectrocardiographyElectric InjuriesEquipment SafetyCardiac OutputAnti-Arrhythmia AgentsOut-of-Hospital Cardiac ArrestHeart FailureHeartAmiodaroneDevice RemovalTreatment OutcomeEquipment DesignCardiomyopathiesElectrodes, ImplantedCardiac Surgical ProceduresEquipment Failure AnalysisFollow-Up StudiesVentricular Dysfunction, LeftCardiac Resynchronization Therapy DevicesStroke VolumeHeart DiseasesTime FactorsProsthesis ImplantationCardiac ElectrophysiologyTachycardiaEmergency Medical ServicesHeart VentriclesSyncopeProspective StudiesVolunteersElectrophysiologic Techniques, CardiacCardiomyopathy, DilatedCardiography, ImpedanceRisk AssessmentBrugada SyndromeRetrospective StudiesMyocardial InfarctionMyocardiumCardiac CatheterizationAtrial FibrillationSurvival RateRisk FactorsCardiomegalyCardiac TamponadeResuscitationDeath, SuddenHeart RateHeart Conduction SystemSurvival AnalysisEchocardiographyElectrocardiography, AmbulatoryMyocardial IschemiaVentricular Function, LeftTachycardia, SupraventricularFirst AidEmergency TreatmentMyocardial ContractionBurns, ElectricHeart TransplantationCardiac Output, LowHeart MassageAdrenergic beta-AntagonistsAircraftCardiomyopathy, HypertrophicVentricular DysfunctionArrhythmogenic Right Ventricular DysplasiaTherapy, Computer-AssistedKaplan-Meier EstimateBundle-Branch BlockCommotio CordisAxillary VeinVentricular RemodelingTachycardia, SinusEmergency Medical TechniciansElectromagnetic PhenomenaRemote Sensing TechnologyHeart Function TestsMyoblasts, CardiacCost-Benefit AnalysisAmbulancesEquipment and SuppliesHeart InjuriesPrimary PreventionCardiac MyosinsCardiac Imaging TechniquesPredictive Value of Tests