San Francisco Syncope Rule
Check five clinical criteria to determine whether an ED patient presenting with syncope is at high risk for a serious outcome within 7 days.
SFSR Criteria
If any one criterion is present, the rule is positive (high risk). All five must be absent for a negative result.
1. History of congestive heart failure (CHF)
2. Hematocrit < 30% (HCT)
3. Abnormal ECG on presentation (ECG)
New change vs. prior, non-sinus rhythm, ST/T change, or conduction defect.
4. Shortness of breath (SOB)
Dyspnea with the syncopal episode or on presentation.
5. Systolic BP < 90 mmHg at triage (SBP)
Select all five criteria and click Calculate Risk to see the result.
SFSR Result
POSITIVE — High Risk
One or more criteria present. Patient is at high risk for a serious outcome within 7 days.
Suggested Action
Consider hospital admission or an accelerated evaluation pathway with cardiology or relevant specialty. Disposition should be guided by the full clinical picture and local protocols.
For educational use only. All clinical decisions must be made by a qualified clinician.
SFSR Result
NEGATIVE — Low Risk
All five criteria absent. Patient screens as low risk per the SFSR.
All five criteria were absent:
- No history of CHF
- Hematocrit ≥ 30%
- Normal ECG
- No shortness of breath
- Systolic BP ≥ 90 mmHg at triage
Suggested Action
May support consideration of discharge with close follow-up, depending on full clinical context. The SFSR has ~96% sensitivity — a negative result reduces but does not eliminate risk.
For educational use only. All clinical decisions must be made by a qualified clinician.
SFSR Quick Reference
| Criterion | Threshold |
|---|---|
| CHF History | Prior documented diagnosis |
| Hematocrit | < 30% |
| ECG | Any abnormality |
| Shortness of Breath | With or on presentation |
| Systolic BP | < 90 mmHg at triage |
Any single criterion present = POSITIVE (high risk). All absent = NEGATIVE (low risk). Sensitivity ~96%, Specificity ~62% (Quinn et al., 2004).
Summary
Check five clinical criteria to determine whether an ED patient presenting with syncope is at high risk for a serious outcome within 7 days.
How it works
- Review the patient's history, vital signs, ECG, and hematocrit from the ED workup.
- For each of the five SFSR criteria, select "Present" or "Absent".
- If ANY criterion is present, the rule is POSITIVE and the patient is high risk.
- Only when ALL five criteria are absent is the rule NEGATIVE (low risk).
- Use the result to guide disposition — the tool does not replace clinical judgment.
Use cases
- Triaging ED patients who present with a chief complaint of syncope or near-syncope.
- Deciding whether a patient warrants hospital admission versus safe discharge.
- Educational reference for residents and medical students learning syncope evaluation.
- Rapid bedside risk communication before ordering additional tests.
- Quality assurance audits of syncope management protocols.