Improving Management of Emergency Department Patients With Undifferentiated Syncope: Prospective Validation of the Canadian Syncope Risk Score

Inclusion Criteria: * Age ≥16y * Member of Kaiser Permanente Northern California (KPNC) health plan * Presentation to the ED with an ED diagnosis of recent syncope or presyncope (\<24h) without a serious etiology identified during the initial ED diagnostic assessment, that is, patients with unexplained syncope. * Subjects who meet criteria will be identified electronically within the CDS tool in the electronic health record. Exclusion Criteria: * Age \<16 years old * Non-members of KPNC * Patients with obvious witnessed seizure, prolonged loss of consciousness (\>5 minutes), post-traumatic loss of consciousness, and new mental status changes * Patients requiring hospitalization for traumatic injuries (e.g., syncope leading to motorized vehicle collision), because their outcomes may be related to trauma rather than syncope * Patients with impaired communication capacity, e.g., intoxication, language barriers, and dementia.