title: A first-degree family history in lone atrial fibrillation patients.
abstract: BACKGROUND
  Atrial fibrillation (AF) may be due to an inherited trait, particularly in lone AF patients. A family history of AF in lone AF patients has not previously been compared with a family history of patients with AF and established risk factors (non-lone AF).
  
  
  OBJECTIVE
  The purpose of this study was to compare the frequency of having a first-degree relative with AF in lone and non-lone AF patients.
  
  
  METHODS
  We performed a case-control study of consecutive subjects presenting to a single electrophysiology laboratory. A convenience sample of subjects with no known arrhythmias was also enrolled.
  
  
  RESULTS
  Four hundred twenty-nine subjects were enrolled: 136 had AF (54 with lone AF), 84 had atrial flutter, 158 had other supraventricular arrhythmias, and 51 had no known arrhythmias. Significantly more subjects with AF reported a first-degree family history of AF compared with the remainder of the cohort (25% vs. 5%; P <.001). In multivariable analysis adjusting for potential confounders, AF patients had a 6-fold greater odds of having a family member with AF (95% confidence interval [CI] 2.93-12.7; P <.001). Lone AF patients had a first-degree family member with AF substantially more often than those with non-lone AF (41% vs. 14%; P <.001). After adjusting for potential confounders, lone AF patients remained significantly more likely than other AF patients to have a first-degree relative with AF (OR 7.2; 95% CI 2.1-24.7; P = .002).
  
  
  CONCLUSIONS
  Lone AF patients have a first-degree family member with AF substantially more often than other AF patients. This suggests that an inherited trait may be particularly important in this subgroup of patients.
authors.affiliation: Division of Cardiology, Electrophysiology Section, University of California, San Francisco, California, USA. marcusg@medicine.ucsf.edu
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Marcus
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Smith
authors.forename: Eric
authors.initials: E
authors.lastname: Vittinghoff
authors.forename: Zian H
authors.initials: ZH
authors.lastname: Tseng
authors.forename: Nitish
authors.initials: N
authors.lastname: Badhwar
authors.forename: Byron K
authors.initials: BK
authors.lastname: Lee
authors.forename: Randall J
authors.initials: RJ
authors.lastname: Lee
authors.forename: Melvin M
authors.initials: MM
authors.lastname: Scheinman
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Olgin
mesh_terms: D001281:Atrial Fibrillation / Q000235:genetics* / Q000503:physiopathology; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008487:Medical History Taking; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires