San Francisco syncope rule calculator

San Francisco Syncope Rule

San Francisco Syncope Rule (CHESS)

Criteria (CHESS)	No	Yes
C — History of CHF	1
H — Hematocrit <30%	1
E — Abnormal ECG (new changes or non-sinus rhythm)	1
S — Shortness of breath	1
S — Systolic BP <90 mmHg at triage	1
Risk Factors	/ 5

Interpretation
0	Low risk — 2% risk of serious outcome at 30 days. Consider discharge with outpatient follow-up.
≥1	Not low risk — Cannot be classified as low risk. Consider further workup or admission.

References

Quinn JV, Stiell IG, McDermott DA, et al. Derivation of the San Francisco Syncope Rule. Ann Emerg Med. 2004;43(2):224-232. PMID 14747812. Quinn JV, Stiell IG, McDermott DA, et al. The San Francisco Syncope Rule vs physician judgment and decision making. Am J Emerg Med. 2005;23:782-786. Note: Sensitivity ~98% for serious outcomes. Some validation studies show lower performance. Use with clinical judgment.