Defibrillators, ImplantableVentricular FibrillationType D PersonalityTachycardia, VentricularEquipment FailureElectric CountershockEquipment SafetyArrhythmias, CardiacDeath, Sudden, CardiacAnti-Arrhythmia AgentsAnxietyElectrocardiographyRisk FactorsProspective StudiesTreatment OutcomeElectric InjuriesAmiodaroneInternational Classification of DiseasesPrimary PreventionPacemaker, ArtificialDevice RemovalConvulsive TherapyImpulse Control DisordersFollow-Up StudiesElectrophysiologic Techniques, CardiacProsthesis ImplantationHeart FailureCardiac Pacing, ArtificialCardiac ElectrophysiologyEquipment Failure AnalysisCardiac Resynchronization TherapyCardiomyopathy, Dilated