Prognostic role of previous syncope spells in ED patients with syncope

In the prognostic evaluation of syncopal patients, previous episodes have a somewhat ambivalent role, as they are usually associated to reflex syncope, with a benign prognosis, but according to some authors when frequent require further investigations even in case of a negative ED workup.

Retrospective observational study in a cohort of 378 ED syncopal patients to investigated the presence of previous episodes and their prognostic significance, in predicting cardiac syncope, syncope associated to underlying acute diseases and syncope severe due to consequential risk.

We found previous syncopal episodes in over half of patients (57.4 %); mostly few (up to two episodes in total in 63.8 %), with a trends over time very rare or occasional, in a small minority complicated by major injuries. As regards the prognostic role of syncopal recurrences, we found: 1. no association between their total number in life with any outcome considered; 2. a close association between presence of acute principal diseases and absence of previous episodes; 3. a close association between severe syncope due to consequential risk and a frequent or recurrent time course of previous spells and previous episodes worsened by major injuries.

Previous episodes, although frequent, don't correlate with adverse outcomes so don't help to identify high risk patients. Conversely, a first syncopal episode, especially in elderly patients, requires careful evaluation to rule out any underlying acute condition. Additionally, attention should be also paid to patients with previous episodes clustered in the last period or complicated by severe injuries, as they negatively impact quality of life.