title: Stepwise evaluation of syncope: a prospective population-based controlled study.
abstract: BACKGROUND
  Evaluation of syncope remains often unstructured. The aim of the study was to assess the effectiveness of a standardized protocol designed to improve the diagnosis of syncope.
  
  
  METHODS
  Consecutive patients with syncope presenting to the emergency departments of two primary and tertiary care hospitals over a period of 18 months underwent a two-phase evaluation including: 1) noninvasive assessment (phase I); and 2) specialized tests (phase II), if syncope remained unexplained after phase I. During phase II, the evaluation strategy was alternately left to physicians in charge of patients (control), or guided by a standardized protocol relying on cardiac status and frequency of events (intervention). The primary outcomes were the diagnostic yield of each phase, and the impact of the intervention (phase II) measured by multivariable analysis.
  
  
  RESULTS
  Among 1725 patients with syncope, 1579 (92%) entered phase I which permitted to establish a diagnosis in 1061 (67%) of them, including mainly reflex causes and orthostatic hypotension. Five-hundred-eighteen patients (33%) were considered as having unexplained syncope and 363 (70%) entered phase II. A cause for syncope was found in 67 (38%) of 174 patients during intervention periods, compared to 18 (9%) of 189 during control (p<0.001). Compared to control periods, intervention permitted diagnosing more cardiac (8%, vs 3%, p=0.04) and reflex syncope (25% vs 6%, p<0.001), and increased the odds of identifying a cause for syncope by a factor of 4.5 (95% CI: 2.6-8.7, p<0.001). Overall, adding the diagnostic yield obtained during phase I and phase II (intervention periods) permitted establishing the cause of syncope in 76% of patients.
  
  
  CONCLUSIONS
  Application of a standardized diagnostic protocol in patients with syncope improved the likelihood of identifying a cause for this symptom. Future trials should assess the efficacy of diagnosis-specific therapy.
authors: Emergency Center, Hopital Cantonal, University of Geneva Medical School, Geneva, Switzerland. francois.sarasin@hcuge.ch
authors: François P
authors: FP
authors: Sarasin
authors: Etienne
authors: E
authors: Pruvot
authors: Martine
authors: M
authors: Louis-Simonet
authors: Olivier W
authors: OW
authors: Hügli
authors: Juan M
authors: JM
authors: Sztajzel
authors: Jürg
authors: J
authors: Schläpfer
authors: Monica
authors: M
authors: Herrera
authors: Johan
authors: J
authors: Graz
authors: Christophe
authors: C
authors: Berchier
authors: Corinne
authors: C
authors: Mischler
authors: Bertrand
authors: B
authors: Yersin
mesh_terms: D000368:Aged; D016009:Chi-Square Distribution; D015897:Comorbidity; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D011446:Prospective Studies; D013575:Syncope / Q000175:diagnosis* / Q000209:etiology* / Q000401:mortality; D016896:Treatment Outcome