Interactive Corrected QT Interval (QTc) calculator using Bazett's formula. Requires the calculator gadget.
Usage: {{QTc Calculator}}
Corrected QT Interval (QTc)
Corrected QT Interval (QTc)
| Parameter
|
Value
|
| QT Interval (ms)
|
|
| Heart Rate (bpm)
|
|
| RR Interval (ms) — auto-calculated from HR
|
ms
|
| Results
|
| QTc (Bazett's) — QT / √(RR in sec)
|
ms
|
| QTc (Fridericia) — QT / ∛(RR in sec)
|
ms
|
| Interpretation (Bazett's QTc)
|
| <440 ms
|
Normal QTc for males.
|
| <460 ms
|
Normal QTc for females.
|
| 440–500 ms
|
Borderline/Prolonged — Monitor closely. Review medications for QT-prolonging drugs.
|
| >500 ms
|
Significantly prolonged — High risk for Torsades de Pointes. Discontinue offending agents. Check Mg²⁺/K⁺/Ca²⁺.
|
| References
|
- Bazett HC. An analysis of the time-relations of electrocardiograms. Heart. 1920;7:353-370.
- Fridericia LS. Duration of systole in electrocardiogram. Acta Med Scand. 1920;53:469-486.
- Viskin S. Long QT syndromes and torsade de pointes. Lancet. 1999;354:1625-1633. PMID 10560690.
|
