According to a prospective study (the SPEED Study) presented by Yvonne Greve of Nuremberg Hospital et al. in Deutsches Ärzteblatt International (Dtsch Arztebl Int 2014; 111(12): 197), up to 3% of consultations at an emergency department concern a sudden loss of consciousness or near loss of consciousness.
In order to assess the frequency and prognostic significance of near syncope and syncope (the specialist terms for short-term near or complete loss of consciousness), the authors gathered data on 395 patients who presented to an emergency department with the typical symptoms.
Emergency department consultations for near syncope or syncope were relatively frequent, accounting for approximately 3% of cases. Most of these patients (62%) attended the emergency department for complete loss of consciousness; the remaining 38% for near loss of consciousness. The overall rate of adverse events--including myocardial infarction or even sudden death--during follow-up was high, at 32%. There were no differences between the two patient groups in terms of the type or frequency of adverse events.
Patients with near syncope had similar characteristics and comorbidities to those with syncope. They also had similar risk profiles and prognoses. The authors therefore recommend that patients with near loss of consciousness be examined with the same level of standardization and thoroughness as those who lose consciousness completely.