What does a positive SFSR result mean?

One or more positive criteria indicates HIGH RISK — the patient had a roughly 25% rate of serious outcome at 7 days in the original validation study. Admission or urgent workup is generally warranted.

What counts as an abnormal ECG?

Any new change vs. prior ECG, or a tracing showing a non-sinus rhythm, bundle branch block, prolonged QT, Wolff-Parkinson-White pattern, or evidence of ischemia. A normal sinus rhythm with no acute changes is not abnormal.

What are the serious outcomes the SFSR predicts?

Death, MI, arrhythmia, pulmonary embolism, stroke/TIA, subarachnoid hemorrhage, significant hemorrhage, or any condition causing a return ED visit and subsequent hospital admission within 7 days.

What does a shortness of breath criterion indicate?

Dyspnea at triage or on history suggests a cardiopulmonary cause (PE, acute heart failure) that significantly raises short-term mortality risk after syncope.

How accurate is the SFSR?

The original Quinn et al. study (2004) reported sensitivity ~96% and specificity ~62% for serious outcomes. Subsequent external validations showed lower sensitivity (60–80%), so clinical context remains essential.

Can I use SFSR to discharge a patient?

A negative SFSR (all 5 criteria absent) supports low-risk status, but clinical judgment, the full history, and institutional protocol should guide any discharge decision.

San Francisco Syncope Rule

Apply the 5-criterion San Francisco Syncope Rule to stratify ED syncope patients by 7-day serious outcome risk.

SFSR Criteria

Check every criterion that is present. Any single positive = HIGH RISK.

Abnormal ECG

New change vs. prior, or non-sinus rhythm, BBB, prolonged QT, WPW, or ischemic changes.

Shortness of Breath

Chief complaint of dyspnea at triage or by history at presentation.

Systolic BP < 90 mmHg at Triage

Initial triage systolic blood pressure below 90 mmHg.

Hematocrit < 30%

Point-of-care or lab hematocrit below 30% (suggests significant anemia or acute blood loss).

History of Congestive Heart Failure

Known CHF documented in past medical history or chart.

Result

Positive criteria

0 of 5 criteria positive

Criteria Breakdown

Clinical tool only. SFSR aids, but does not replace, physician judgment. Always integrate full history, physical exam, and institutional protocols.

Summary

The San Francisco Syncope Rule (SFSR) uses five clinical criteria — abnormal ECG, complaint of shortness of breath, systolic BP < 90 mmHg at triage, hematocrit < 30%, and a history of congestive heart failure — to flag ED syncope patients at high risk for serious outcomes within 7 days. Any single positive criterion classifies the patient as high risk. The rule was derived and validated by Quinn et al. (Ann Emerg Med, 2004) and is widely used as a rapid bedside risk-stratification aid.

How it works

Assess each of the 5 binary criteria from triage vitals, point-of-care labs, and the 12-lead ECG.
A single "yes" answer makes the rule positive (high risk).
All five "no" answers makes the rule negative (low risk).
Sensitivity ~96%, specificity ~62% in the derivation cohort for 7-day serious outcomes.
Use alongside full clinical assessment — SFSR does not cover all causes of syncope.

Use cases

Rapid ED triage of syncope patients to determine admission vs. discharge.
Documenting risk stratification reasoning in ED charts.
Teaching medical students the validated SFSR criteria.
Comparing with other syncope rules (ROSE, Boston, Canadian) in clinical decision support.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu