San Francisco Syncope Rule

Identify those at low risk of adverse outcome after a syncopal episode


The San Francisco Syncope rule identifies patients who cannot be considered low risk of adverse outcomes after a syncopal event.

Criteria include:

  • History of congestive heart failure
  • Hematocrit <30%
  • Abnormal EKG (New ECG change from any source, any non-sinus rhythm on EKG or monitoring)
  • Symptoms of shortness of breath
  • Systolic BP <90 mmHg at triage

If any of these criteria are noted, patient cannot be considered "low risk" of a serious outcome. In this study, a serious outcome is defined as "death, myocardial infarction, arrhythmia, pulmonary embolism, stroke, subarachnoid hemorrhage, significant hemorrhage, or any condition causing a return ED visit and hospitalization for a related event."

While the original paper identified a 96% sensitivity and 62% specificity for serious outcome (with negative predictive value 99.2% and positive predictive value 24.8%), validation studies have reported inconsistent results.


Quinn J, McDermott D, Stiell I, Kohn M, Wells G.

Annals of Emergency Medicine 2006, 47 (5): 448-54

Birnbaum A, Esses D, Bijur P, Wollowitz A, Gallagher EJ.

Annals of Emergency Medicine 2008, 52 (2): 151-9

The San Francisco Syncope Rule calculator is created by QxMD.

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1. History of Heart Failure?

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