Syncope: vasovagal and 'unknown cause' were the commonest findings in the emergency department.

Clinical bottom line (level 2b)

  1. Two thirds of patients attending the emergency department with syncope had a vasovagal episode or never had a cause found.
  2. Other causes were much less common and included first seizures (9%), orthostatic hypotension (8%) and cardiac arrhythmias (4%).
Martin et al: Annals of Emergency Medicine 1984; 13: 499-504
Expires October 2004

The study

Prospective cohort study with objective outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: emergency department, university hospital, USA

170 patients (aged range 18 to 88 years; mean 41, ?% male) syncope (less than 30 minutes loss of consciousness)

Excluded if
  • <18 years old
  • presyncope or dizzy without loss of consciousness




    • 86% followed for mean 6 months
    Outcomes studied:
  • admitted
  • cause: unknown
  • vasovagal
  • first seizure
  • orthostatic
  • cardiac arrhythmia
  • micturition
  • hypoglycaemia
  • psychiatric

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    admitted mean 6 months 44/170 26%
    (19% to 32%)
    cause: unknown mean 6 months 64/170 38%
    (30% to 45%)
    vasovagal mean 6 months 63/170 37%
    (30% to 44%)
    first seizure mean 6 months 15/170 8.8%
    (4.6% to 13%)
    orthostatic mean 6 months 13/170 7.7%
    (3.7% to 12%)
    cardiac arrhythmia mean 6 months 7/170 4.1%
    (1.1% to 7.1%)
    micturition mean 6 months 4/170 2.4%
    (0.074% to 4.6%)
    hypoglycaemia mean 6 months 3/170 1.8%
    (0.0% to 3.7%)
    psychiatric mean 6 months 1/170 0.59%
    (0.0% to 1.7%)

    Citation

    1. Martin GJ, Adams SL, Martin HG, et al: Prospective evaluation of syncope. Annals of Emergency Medicine 1984; 13: 499-504
    Contributor: Chris Ball and Clare Wotton, October 2000
    Reviewer: Michael Christian

    Clinical Question.
    Patient syncope
    Intervention or Exposure prevalence
    Outcome cause found