Canadian Syncope Risk Score (CSRS)
30-day risk of serious outcomes after emergency-department assessment of syncope
Sources last checked: 2026-11-03
Canadian Syncope Risk Score (CSRS)
30-day risk of serious outcomes after emergency-department assessment of syncope
For adults (≥ 16 years) presenting within 24 h of syncope in whom no serious cause was identified during the ED evaluation. Not for presyncope, seizure, intoxication, or loss of consciousness from trauma. The ED diagnosis item is the treating physician's judgement at disposition.
Interpretation
| Very low risk | Score −3 to −2. In the 2020 validation 3 of 1631 patients (0.2 %) had a 30-day serious outcome; none died or had a ventricular arrhythmia. |
|---|---|
| Low risk | Score −1 to 0. 0.7 % (9/1254) had a 30-day serious outcome in the validation cohort; the authors state that very-low- and low-risk patients can generally be discharged. |
| Medium risk | Score 1 to 3. 8.0 % (55/687) had a 30-day serious outcome in the validation cohort. |
| High risk | Score 4 to 5. 19.2 % (32/167) had a 30-day serious outcome; the authors suggest brief hospitalisation can be considered for high-risk patients. |
| Very high risk | Score 6 to 11. 51.3 % (40/78) had a 30-day serious outcome in the validation cohort. |
What is the Canadian Syncope Risk Score (CSRS)?
The Canadian Syncope Risk Score (CSRS) estimates the 30-day risk of serious adverse events — death, arrhythmia, myocardial infarction, structural heart disease, pulmonary embolism, serious haemorrhage or procedural intervention — after an emergency visit for syncope. Thiruganasambandamoorthy and colleagues derived it in 4,030 adults at six Canadian emergency departments (CMAJ 2016) and validated it in 3,819 patients at nine sites (JAMA Intern Med 2020). It combines clinical history, blood pressure, troponin, three ECG measurements and the physician's ED diagnosis.
When to use it
- Adults (≥ 16 years) presenting within 24 h of syncope after the initial ED work-up has not found a serious cause.
- Supporting disposition decisions: discharge, observation or admission.
- Communicating risk to patients and colleagues with category-specific event rates.
When not to use it
- When a serious cause has already been found in the ED (e.g. arrhythmia on monitoring, acute coronary syndrome, PE).
- Presyncope, seizure, intoxication, or loss of consciousness after head trauma.
- Patients under 16 years.
How it is calculated
| Criterion | Points |
|---|---|
| Predisposition to vasovagal symptoms (triggered by a warm crowded place, prolonged standing, fear, emotion or pain) | -1 |
| History of heart disease (coronary or valvular disease, cardiomyopathy, heart failure, non-sinus rhythm) | +1 |
| Any systolic BP < 90 or > 180 mmHg in the ED (triage to disposition) | +2 |
| Troponin above the 99th percentile of the normal population | +2 |
| Abnormal QRS axis (< −30° or > 100°) | +1 |
| QRS duration > 130 ms | +1 |
| Corrected QT interval > 480 ms | +2 |
| Emergency-department diagnosis | |
| Neither vasovagal nor cardiac syncope | 0 |
| Vasovagal syncope | -2 |
| Cardiac syncope | 2 |
Clinical pearls and limitations
- For adults (≥ 16 years) presenting within 24 h of syncope in whom no serious cause was identified during the ED evaluation. Not for presyncope, seizure, intoxication, or loss of consciousness from trauma. The ED diagnosis item is the treating physician's judgement at disposition.
- Two items can lower the score: a vasovagal predisposition (−1) and an ED diagnosis of vasovagal syncope (−2).
- The ED diagnosis item is a three-way choice — vasovagal (−2), cardiac (+2) or neither (0).
- Any systolic pressure < 90 or > 180 mmHg counts, from triage until disposition, not just the first reading.
- In the validation no very-low- or low-risk patient died or had a ventricular arrhythmia; at a threshold of −1 sensitivity was 97.8 %.
- Troponin uses the 99th percentile of the local assay; a troponin is needed for a complete score.
Frequently asked questions
How is the Canadian Syncope Risk Score calculated?
Add points for nine items: vasovagal predisposition −1, heart disease +1, systolic BP < 90 or > 180 mmHg +2, raised troponin +2, abnormal QRS axis +1, QRS > 130 ms +1, QTc > 480 ms +2, and ED diagnosis vasovagal −2 or cardiac +2. The total runs from −3 to 11.
What CSRS score is low risk?
−3 to −2 is very low and −1 to 0 low risk; in the 2020 validation 0.2 % and 0.7 % of these patients had a serious outcome within 30 days.
Canadian Syncope Risk Score vs San Francisco Syncope Rule — which is better?
The CSRS gives five graded risk categories and was validated prospectively at nine centres; the San Francisco rule is a binary rule whose sensitivity varied widely in external validation (pooled 87 %).
Is the CSRS validated outside Canada?
The derivation and the 2020 validation were both Canadian multicentre studies; performance elsewhere depends on local validation.
Evidence and guidelines
- Primary source: Thiruganasambandamoorthy V, Kwong K, Wells GA et al. Development of the Canadian Syncope Risk Score to predict serious adverse events after emergency department assessment of syncope. CMAJ 2016;188(12):E289-E298.
- Thiruganasambandamoorthy V, Sivilotti MLA, Le Sage N et al. Multicenter emergency department validation of the Canadian Syncope Risk Score. JAMA Intern Med 2020;180(5):737-744 — Table 1 (points) and Table 3 (risk categories).
Have a follow-up question?
Medelix answers clinical questions from current guidelines and studies — every statement with its source.
Related calculators
Embed this calculatorFree to use on your website, intranet or teaching page. Copy the code below.
<iframe src="https://medelix.ai/en/embed/canadian-syncope-risk-score" title="Canadian Syncope Risk Score (CSRS) – Medelix" width="100%" height="620" style="border:0;max-width:720px" loading="lazy"></iframe>
<p><a href="https://medelix.ai/en/calculators/canadian-syncope-risk-score">Canadian Syncope Risk Score (CSRS) calculator by Medelix</a></p>For healthcare professionals and medical students. These tools support, and do not replace, clinical judgement. Always check results against the original source and your local protocols.