Bazett’s Formula: QTc by QT and Heart Rate
NOTE: This page is only intended as a visualization of Bazett’s formula. Assessment of arrythmias should only be done by qualified healthcare professionals.
Bazett’s formula is used to correct the QT interval for heart rate, which is important for assessing the risk of arrhythmias. The formula is given by:
\[ QTc = \frac{QT}{\sqrt{\frac{60}{HR}}}= \frac{QT}{\sqrt{RR}} \]
where:
- QT is the QT interval in milliseconds,
- HR is the heart rate in beats per minute (bpm),
- QTc is the corrected QT interval.
QTc Calculator
Enter either heart rate (HR) or RR interval, and the QT interval:
Reference
Bazett, H.C. (1920) An Analysis of the Time-Relations of Electrocardiograms. Heart, 7, 353-370.
TARAN LM, SZILAGYI N. The duration of the electrical systole, Q-T, in acute rheumatic carditis in children. Am Heart J. 1947 Jan;33(1):14-26. doi: 10.1016/0002-8703(47)90421-3