title: Implantable loop recorder allows an etiologic diagnosis in one-third of patients. Results of the Spanish reveal registry.
abstract: BACKGROUND
  The implantable loop recorder (ILR) is a useful tool for diagnosing paroxysmal conditions potentially related to arrhythmias. Most investigations have focused on selected clinical studies or high-volume centers. The aim of this study was to evaluate the indications and outcomes of the ILR in real clinical practice.
  
  
  RESULTS
  This was a prospective, multicenter registry of patients undergoing ILR implantation for clinical indications (April 2006-December 2008). Clinical characteristics (symptoms, arrhythmias, treatments) were recorded in a database. Follow-up data at 1 year or after the occurrence of the first episode were also recorded. Total enrollment: 743 patients (male, 413, 55.6%; 64.9 ± 16 years); 228 (30.7%) had structural heart disease (SHD), and 183 (24.6%), bundle branch block (BBB). Recurrent syncope (76.4%) was the most common indication for implantation. Complete follow-up was obtained for 680 patients (91.5%). Three hundred and twenty-five patients (48%) presented 414 events, with a final diagnosis in 230 patients (70.8% of patients with events; 33.1% of patients with follow-up). Syncope secondary to bradyarrhythmia was the most frequent diagnosis. Similar rates of final diagnoses were noted in subgroups of SHD, BBB and normal heart. Regarding the cause of implantation, higher event rates were registered among patients with recurrent syncope.
  
  
  CONCLUSIONS
  One-third of patients obtained a final diagnosis with the ILR, independent of the baseline characteristics. Only the cause of implantation provided different rates of final diagnosis.
authors.affiliation: Hospital Universitario Virgen de la Arrixaca.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Lacunza-Ruiz
authors.forename: Angel
authors.initials: A
authors.lastname: Moya-Mitjans
authors.forename: Jesús
authors.initials: J
authors.lastname: Martínez-Alday
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Barón-Esquivias
authors.forename: Ricardo
authors.initials: R
authors.lastname: Ruiz-Granell
authors.forename: Nuria
authors.initials: N
authors.lastname: Rivas-Gándara
authors.forename: Susana
authors.initials: S
authors.lastname: González-Enríquez
authors.forename: Juan
authors.initials: J
authors.lastname: Leal-del-Ojo
authors.forename: María F
authors.initials: MF
authors.lastname: Arcocha-Torres
authors.forename: Julian
authors.initials: J
authors.lastname: Pérez-Villacastín
authors.forename: Natalie
authors.initials: N
authors.lastname: Garcia-Heil
authors.forename: Arcadi
authors.initials: A
authors.lastname: García-Alberola
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001145:Arrhythmias, Cardiac / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D016208:Databases, Factual; D004567:Electrodes, Implanted; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012042:Registries; D012189:Retrospective Studies; D013030:Spain