Syncope: common causes were orthostatic hypotension and vasovagal syncope

Clinical bottom line (level 2b)

  1. Common causes of syncope in the emergency department were vasovagal syncope and orthostatic hypotension.
Ammirati et al: European Heart Journal 2000; 21 : 935-940
Expires October 2004

The study

Setting: emergency departments, 9 acute hospitals, Italy

195 patients (aged 13 to 95; mean 63, 56% female) presenting with syncope (defined as sudden transient loss of consciousness and of postural tone with spontaneous recovery)

Excluded if
  • known seizure disorder with a prolonged postictal recovery phase
  • no clear loss of consciousness
  • aged <12

    All patients had a history and physical examination, 12-lead ECG and rhythm strip, haemoglobin count, and blood glucose test. If no conclusive diagnosis was reached, patients received further evaluation (based on abnormalities found: for suspected cardiac syncope, echocardiogram; for suspected neurally mediated syncope, carotid sinus massage and head-up tilt testing; and for suspected neurologic or psychiatric syncope, EEG, brain imaging, or carotid Doppler ultrasonography. Patients had further investigations if the diagnosis was still inconclusive.
    ?independent ?blinded reference standard, applied in all patients from a consecutive appropriate spectrum.

    The evidence


    differential diagnosis number of patients prevalence
    (95% CI)
    neurally mediated syncope 69 35%
    (29% to 42%)
    vasovagal syncope 58 30%
    (23% to 36%)
    situational syncope 7 3.5%
    (1.0% to 6.2%)
    carotid sinus syndrome 4 2.1%
    (0.1% to 4.0%)
    cardiac syncope 41 21%
    (15% to 27%)
    bradyarrhythmias 21 11%
    (6.4% to 15%)
    tachyarrhythmias 14 7.2%
    (3.6% to 11%)
    haemodynamic 6 3.1%
    (% to %)
    orthostatic hypotension 12 6.2%
    (2.8% to 9.5%)
    neurologic syncope 27 14%
    (9.0% to 19%)
    cerebrovascular 21 11%
    (6.4% to 15%)
    epilepsy 6 3.1%
    (0.7% to 5.5%)
    psychiatric syncope 11 5.6%
    (2.4% to 8.9%)
    metabolic syncope (hypoglyacemia) 1 0.5%
    (0.0% to 1.5%)
    syncope of unknown origin 34 17%
    (12% to 23%)

    Comments

    1. 22% were diagnosed after initial investigations. 54% were admitted to hospital.
    2. The study failed to provide adequate follow-up to ensure that the correct diagnoses were reached. Many of the vasovagal diagnosese were based on the tilt table test which has a high false positive rate.

    Citation

    1. Ammirati F, Colvicchi F, Santini M, et al: Diagnosing syncope in clinical practice. Implementation of a simplified diagnostic algorithm in a multicentre prospective trialthe OESIL 2 Study (Osservatorio Epidemiologico della Sincope nel Lazio).. European Heart Journal 2000; 21 : 935-940
    Contributor: Chris Ball, October 2001
    Reviewer:

    Clinical Question.
    Patient syncope attending emergency department
    Intervention or Exposure history, physical examination, investigations
    Outcome cause