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Canadian Syncope Risk Score (CSRS)

The Canadian Syncope Risk Score (−3 to 11) estimates 30-day serious adverse events after ED syncope from 9 predictors. Categories: very low (−3 to −2), low (−1 to 0), medium (1–3), high (4–5), very high (≥6); derivation risk ranged from 0.4% at −3 to 83.6% at 11.

  • Predisposition to vasovagal symptoms (warm crowded place, prolonged standing, fear, emotion, pain) (yes/no, -1)
  • History of heart disease (CAD, AF/flutter, CHF, valvular disease) (yes/no, +1)
  • Any ED systolic BP < 90 or > 180 mmHg (yes/no, +2)
  • Elevated troponin (> 99th percentile) (yes/no, +2)
  • Abnormal QRS axis (< −30° or > 100°) (yes/no, +1)
  • QRS duration > 130 ms (yes/no, +1)
  • Corrected QT > 480 ms (yes/no, +2)
  • ED diagnosis: Vasovagal syncope (-2); Neither (e.g. orthostatic or unknown) (0); Cardiac syncope (2)
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Interpretation

ResultMeaning
−3 to −2Very low (0.4–0.7%)
−1 to 0Low (1.2–1.9%)
1 to 3Medium (3.1–8.1%)
4 to 5High (12.9–19.7%)
6 to 11Very high (28.9–83.6%)

Formula

Vasovagal predisposition −1 · heart disease +1 · any ED SBP <90 or >180 +2 · troponin >99th pct +2 · QRS axis <−30° or >100° +1 · QRS >130 ms +1 · QTc >480 ms +2 · ED diagnosis vasovagal −2 / cardiac +2.

Clinical pearls

  • Inclusion: adults ≥16 y presenting within 24 h of syncope. Excluded: LOC >5 min, mental status change from baseline, obvious witnessed seizure, head trauma causing LOC, inability to give history, or major trauma requiring admission.
  • Serious adverse events (30 days): death, MI, arrhythmia, structural heart disease, PE, serious haemorrhage, procedural interventions.
  • A score of −2 or higher had 99.2% sensitivity in derivation; very low and low risk patients are generally suitable for discharge.

Examples

csrs: vasovagal prodrome, no heart disease, bp normal, troponin negative, normal ecg, dx vasovagalcanadian syncope risk 75 yo with CAD, troponin elevated, QRS 140 ms, cardiac syncope

FAQ

What is a low-risk Canadian Syncope Risk Score?

A score of 0 or less (very low: −3 to −2; low: −1 to 0), with an estimated 30-day serious adverse event risk under 2%.

Does troponin need to be measured for the CSRS?

Yes, troponin is one of the nine predictors; if it was not checked, the score cannot be completed as derived.

Evidence

  1. Thiruganasambandamoorthy V et al. Development of the Canadian Syncope Risk Score to predict serious adverse events after emergency department assessment of syncope. CMAJ 2016;188:E289–98.

Emergency & Trauma · Reviewed 2026-10-14 · Methodology