title: Worsening of symptoms before presentation with vasovagal syncope.
abstract: BACKGROUND
  Much of the natural history of vasovagal syncope is unknown. We determined whether patients presenting for care have had a recently worsened syncope frequency.
  
  
  RESULTS
  We compared 208 subjects in the referral-based Prevention of Syncope Trial (POST) and 122 subjects who fainted > or =1 in a community survey study. Their mean ages and gender proportions were similar. The POST population had a higher median lifetime syncope frequency (1.16 vs 0.12 spells/year, P < 0.0001) and more subjects began fainting at age > or =35 years (26% vs 6%, P < 0.0001). In POST, the median frequency of syncopal spells in the preceding year was higher than in all previous years (3 vs 0.57, P < 0.0001). POST subjects presented sooner after their first spell (median 11.0 vs 16.8 years, P = 0.0002), and after their last spell (median 0.3 vs 7.4 years, P < 0.0001). POST subjects > or =35 years old had a shorter history than similar community-survey subjects (2.8 vs 14.9 y, P < 0.0001) and presented earlier after their first syncopal spell than POST subjects with a younger onset of syncope (median 2.8 vs 14.7 y, P < 0.0001), despite having fewer faints (median 6 vs 10, P = 0.0002).
  
  
  CONCLUSIONS
  Many syncope patients present for care after a recent worsening of their frequency of syncope.
authors.affiliation: Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Canada. sheldon@ucalgary.ca
authors.forename: Robert S
authors.initials: RS
authors.lastname: Sheldon
authors.forename: Aaron G
authors.initials: AG
authors.lastname: Sheldon
authors.forename: Anna
authors.initials: A
authors.lastname: Serletis
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Connolly
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Morillo
authors.forename: Thomas
authors.initials: T
authors.lastname: Klingenheben
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Krahn
authors.forename: Mary-Lou
authors.initials: ML
authors.lastname: Koshman
authors.forename: Debbie
authors.initials: D
authors.lastname: Ritchie
mesh_terms: D000328:Adult; D017668:Age of Onset; D002170:Canada / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D012017:Referral and Consultation / Q000706:statistics & numerical data*; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012720:Severity of Illness Index; D019462:Syncope, Vasovagal / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control*; D016896:Treatment Outcome