title: Surveillance after cardiac arrest in patients with Brugada syndrome without an implantable defibrillator: An alarm effect of the previous syncope.
abstract: BACKGROUND
  Debate regarding the prognosis of asymptomatic patients with Brugada syndrome (BrS) is possibly affected by the selection bias of survivors of sudden cardiac arrest (SCA). We aimed to determine variables influencing surveillance after SCA.
  
  
  METHODS
  We analyzed a BrS cohort of 145 patients belonging to 37 families. We compared the clinical data and circumstances surrounding SCA (i.e., place of occurrence and people accompanying the subject) in 10 patients who survived an episode of SCA (Group A) vs. 27 deceased relatives (first or second degree) who suffered sudden cardiac death (SCD; Group B). Information concerning Group B was agreed upon by at least 3 relatives. A sub-analysis was performed considering families carrying a mutation in SCN5A (Group B-Mutant).
  
  
  RESULTS
  Syncope was unique in predicting SCA in the BrS cohort. Comparing Groups A vs. B, there were no differences in the mean age at time of SCA/SCD (46.2 [SD 17.1] vs. 39.9 [SD 14.5] years; p=0.271), gender (male 60% vs. 74.1%; p=0.442), prior cardiomyopathy (0%), administration of cardiovascular treatments (anti-hypertensive and lipid-lowering drugs; 20% vs. 14.8%; p=0.653) or conventional cardiovascular risk factors. Environmental circumstances surrounding the SCA/SCD were not significantly different between groups. Prior syncope was more frequent in Group A (80% vs. 3.7%; p<0.001) and unique in predicting surveillance (p<0.001). Group B-Mutant displayed equivalent data.
  
  
  CONCLUSIONS
  A previous syncope, as an alarm symptom, might contribute to better surveillance of SCA compared with subjects with SCA as the debut of BrS. The latter might behave as a factor of selection bias.
authors.affiliation: Arrhythmia Unit, Cardiology Department, Hospital Universitario Central de Asturias, Oviedo, Spain. Electronic address: dcalvo307@secardiologia.es.
authors.forename: David
authors.initials: D
authors.lastname: Calvo
authors.affiliation: Cardiology Department, Hospital Universitario Central de Asturias, Ovideo, Spain.
authors.forename: Juan Pablo
authors.initials: JP
authors.lastname: Flórez
authors.affiliation: Arrhythmia Unit, Cardiology Department, Hospital de Cabueñes, Gijón, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Valverde
authors.affiliation: Arrhythmia Unit, Cardiology Department, Hospital Universitario Central de Asturias, Oviedo, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Rubín
authors.affiliation: Arrhythmia Unit, Cardiology Department, Hospital Universitario Central de Asturias, Oviedo, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Pérez
authors.affiliation: Arrhythmia Unit, Cardiology Department, Hospital de Cabueñes, Gijón, Spain.
authors.forename: Mar Gonzalez
authors.initials: MG
authors.lastname: Vasserot
authors.affiliation: Cardiology Department, Hospital Universitario Central de Asturias, Ovideo, Spain.
authors.forename: Julián
authors.initials: J
authors.lastname: Rodríguez-Reguero
authors.affiliation: Cardiology Department, Hospital Universitario Central de Asturias, Ovideo, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Avanzas
authors.affiliation: Cardiology Department, Hospital Universitario Central de Asturias, Ovideo, Spain.
authors.forename: Jesús María
authors.initials: JM
authors.lastname: de la Hera
authors.affiliation: Department of Molecular Genetics, Hospital Universitario Central de Asturias, Oviedo, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Gómez
authors.affiliation: Department of Molecular Genetics, Hospital Universitario Central de Asturias, Oviedo, Spain.
authors.forename: Eliecer
authors.initials: E
authors.lastname: Coto
authors.affiliation: Department of Statistics, Hospital Universitario Central de Asturias, Oviedo, Spain; Department of statistics, Universidad Autonoma de Chile, Santiago, Chile.
authors.forename: Pablo
authors.initials: P
authors.lastname: Martínez-Camblor
authors.affiliation: Cardiology Department, Hospital Universitario Central de Asturias, Ovideo, Spain.
authors.forename: César
authors.initials: C
authors.lastname: Morís
mesh_terms: D000328:Adult; D053840:Brugada Syndrome / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D056902:Clinical Alarms; D017147:Defibrillators, Implantable; D005260:Female; D006323:Heart Arrest / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013575:Syncope / Q000175:diagnosis* / Q000401:mortality / Q000503:physiopathology
keywords: Brugada syndrome; Sudden cardiac death; Syncope