title: Vasovagal syncope in medical students and their first-degree relatives.
abstract: OBJECTIVE
  To determine the effect of family history on the likelihood of vasovagal syncope.
  
  
  RESULTS
  Sixty-two medical students and 228 first-degree relatives were studied. Vasovagal syncope was ascertained with the Calgary syncope symptom score. The effects of the sex of the subject and parental syncope history on the likelihood of offspring fainting were described using Kaplan-Meier estimates and analysed using proportional hazards regression. The prevalence of vasovagal syncope was 32% and the median age of first faint in those who fainted was 14 years. More females than males fainted [42 vs. 31%; P=0.02; hazard ratio (HR) 1.34 (95% CI 1.07-1.68)]. An individual with two fainting parents was more likely to faint than one with no fainting parents [P<0.0001; HR 3.4 (95% CI 1.7-7.03)]. In the proportional hazards model, offspring of either sex whose mother faints are more likely to faint than those whose mother does not faint [HR 2.86 (95% CI 1.54-5.31)]. Having a father who faints significantly increases the risk of syncope in sons [HR 4.12 (95%CI 1.39-12.31)], but not in daughters [HR 1.18 (95% CI 0.56-3.34)].
  
  
  CONCLUSIONS
  Family history and sex of subject are important predictors of vasovagal syncope in offspring.
authors.affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N2.
authors.forename: Anna
authors.initials: A
authors.lastname: Serletis
authors.forename: Sarah
authors.initials: S
authors.lastname: Rose
authors.forename: Aaron G
authors.initials: AG
authors.lastname: Sheldon
authors.forename: Robert S
authors.initials: RS
authors.lastname: Sheldon
mesh_terms: D000328:Adult; D032721:Adult Children; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010290:Parents; D010375:Pedigree; D016016:Proportional Hazards Models; D012737:Sex Factors; D013337:Students, Medical; D019462:Syncope, Vasovagal / Q000235:genetics*