Clinical Resources
Long QT Schwartz Score
Diagnostic Probability Score for Congenital Long QT Syndrome
Enter the QTc and check all applicable criteria. Score updates live. Excludes secondary causes of QT prolongation.
ECG Findings
0 pts
QTc (Bazett formula)
ms
Measured at rest, corrected by Bazett (QT/√RR)
— pts
Clinical History
0 pts
Syncope (mutually exclusive — select one)
Family History
0 pts
Family members not previously scored for the same mutation.
QTc Scoring Reference
| QTc (ms) | Points |
|---|---|
| ≥ 480 ms | 3 pts |
| 460 – 479 ms | 2 pts |
| 450 – 459 ms (male only) | 1 pt |
| < 450 ms | 0 pts |
The 450–459 ms threshold applies to males only per the original scoring. This calculator does not automatically apply the sex-specific rule — select the appropriate QTc range manually if applicable.
Applies only to congenital LQTS. Exclude all secondary causes (medications, electrolyte disorders, CNS events). Torsades de pointes and syncope criteria are mutually exclusive — score only one.