Corrected QT interval (QTc)
QTc by Bazett, Fridericia, Framingham, and Hodges side by side.
Inputs
0 of 2ms
bpm
When to use
- Starting or monitoring QT-prolonging drugs.
- Electrolyte disturbance or overdose.
Pearls and pitfalls
- Bazett overcorrects at fast heart rates; Fridericia or Framingham are preferred above about 90 bpm.
- Above 500 ms, or a rise over 60 ms, signals high torsades risk.
Why use
Four formulas at once so you can see the spread.
- where
- QT
- Measured QT, ms
- RR
- RR interval, seconds
- HR
- Heart rate, bpm