title: Age and hemodynamic responses to tilt testing in those with syncope of unknown origin.
abstract: OBJECTIVE
  We sought to determine whether there are age-related differences in vasovagal syncope.
  
  
  BACKGROUND
  In those with suspected vasovagal (neurocardiogenic) syncope, tilt testing demonstrates different hemodynamic responses. These responses may be age related, reflecting differing underlying pathophysiology.
  
  
  METHODS
  Using a two-stage tilt protocol with glyceryl trinitrate (GTN) provocation, 505 consecutive syncopal patients were studied. Their baseline characteristics and hemodynamic responses during both early and tilt-induced collapse were analyzed. Hemodynamic responses were classified using the VAsovagal Syncope International Study (VASIS) criteria: mixed, cardioinhibition, severe cardioinhibition/asystole, pure vasodepression, chronotropic incompetence, and excessive heart rate rise. Multivariate regression analyses were performed to determine the associations of the baseline clinical characteristics (including age) and the tilt-induced hemodynamic responses.
  
  
  RESULTS
  Thirty-three patients were unable to tolerate tilt testing. Age was independently associated with distinct responses during tilt. Chronotropic incompetence was predicted by increasing age (odds ratio [OR] 1.04, p < 0.0002). Younger age predicted an excessive heart rate rise (OR 0.97, p < 0.0005). Pure vasodepression was more common in the older group (>65 years; OR 29.5, p < 0.0001), whereas severe cardioinhibition was much less common in the older age group (OR 0.18, p < 0.0001).
  
  
  CONCLUSIONS
  There appear to be distinct pathophysiologies underlying vasovagal syncope in different age groups. Young people appear to have excessive cardiac and autonomic responses to stress, whereas older patients appear to have a more generalized cardiovascular decline, with attenuated cardiac and autonomic responses to stress.
authors.affiliation: Department of Cardiology, London Chest Hospital, Bonner Road, London E2 9JX, United Kingdom. a_kurbaan@hotmail.com
authors.forename: Arvinder S
authors.initials: AS
authors.lastname: Kurbaan
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Bowker
authors.forename: Nevin
authors.initials: N
authors.lastname: Wijesekera
authors.forename: Ann-Christine
authors.initials: AC
authors.lastname: Franzén
authors.forename: David
authors.initials: D
authors.lastname: Heaven
authors.forename: Sujani
authors.initials: S
authors.lastname: Itty
authors.forename: Richard
authors.initials: R
authors.lastname: Sutton
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D002318:Cardiovascular Diseases / Q000150:complications* / Q000503:physiopathology*; D005260:Female; D018475:Head-Down Tilt / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012720:Severity of Illness Index; D013575:Syncope / Q000209:etiology* / Q000503:physiopathology*; D018667:Tilt-Table Test