The Canadian Syncope Risk Score calculator is designed to assess the likelihood of serious adverse events following an episode of syncope, based on information derived from three areas: clinical evaluation, investigations, and diagnosis in the emergency department.

For the clinical evaluation, the factors contributing to the score include:
- A predisposition to vasovagal symptoms, such as those triggered by a warm crowded place, prolonged standing, or emotional responses, adds 1 point.
- A history of heart disease, including coronary or valvular heart disease, cardiomyopathy, congestive heart failure, or non-sinus rhythm, also adds 1 point.
- Any systolic blood pressure reading below 90 mmHg or above 180 mmHg contributes 2 points.

Regarding investigations:
- An elevated troponin level, exceeding the 99th percentile of the normal population, adds 2 points.
- An abnormal QRS axis (less than -30 degrees or more than 100 degrees) contributes 1 point.
- A QRS duration greater than 130 milliseconds adds 1 point.
- A corrected QT interval extending beyond 480 milliseconds adds 2 points.

Lastly, for the diagnosis made in the emergency department:
- Both vasovagal syncope and cardiac syncope contribute 2 points each to the total score.

Once these individual scores are tabulated, they are summed to arrive at a total score. Based on this score, the calculator offers a risk interpretation, ranging from low to very high:

| Score | Interpretation                                                | Estimated Risk of Serious Adverse Events |
|-------|---------------------------------------------------------------|------------------------------------------|
| -3    | Very low risk                                                 | 0.4%                                     |
| -2    | Very low risk                                                 | 0.7%                                     |
| -1    | Low risk                                                      | 1.2%                                     |
| 0     | Low risk                                                      | 1.9%                                     |
| 1     | Medium risk                                                   | 3.1%                                     |
| 2     | Medium risk                                                   | 5.1%                                     |
| 3     | Medium risk                                                   | 8.1%                                     |
| 4     | High risk                                                     | 12.9%                                    |
| 5     | High risk                                                     | 19.7%                                    |
| 6     | Very high risk                                                | 28.9%                                    |
| 7     | Very high risk                                                | 40.3%                                    |
| 8     | Very high risk                                                | 52.8%                                    |
| 9     | Very high risk                                                | 65.0%                                    |
| 10    | Very high risk                                                | 75.5%                                    |
| 11    | Very high risk                                                | 83.6%                                    |

This interpretation helps gauge the patient's risk level for serious adverse events post-syncope, guiding clinical decision-making and potential management strategies.

The Canadian Syncope Risk Score (CSRS) is a clinical calculator used in the assessment of adult patients who present with syncope, a temporary loss of consciousness usually related to insufficient blood flow to the brain. The CSRS is designed to predict the short-term risk of serious adverse events, such as arrhythmias, myocardial infarction, or death, within 30 days of a syncope episode. This tool aids clinicians in making decisions about hospital admission, further diagnostic testing, and patient management. The CSRS should not be used in patients with obvious causes of loss of consciousness such as seizure or stroke, or in patients with a known diagnosis that readily explains the syncope.

Canadian syncope risk score