Work out qt interval correction (qtc) instantly with clear inputs, formula shown and shareable results.
Corrects a measured QT interval for heart rate using the Bazett, Fridericia and Framingham formulae so the three can be compared.
Corrections
RR = 60/HR; Bazett QTc = QT/sqrt(RR); Fridericia QTc = QT/RR^(1/3); Framingham QTc = QT + 154(1 - RR)
Educational estimate only. Not a substitute for professional clinical judgement, and must not be used to make treatment or dosing decisions.
Bazett over-corrects at fast rates and under-corrects at slow rates, so Fridericia and Framingham are often preferred outside 60-100 bpm.
Commonly quoted thresholds are above 450 ms in men and 460 ms in women, with 500 ms marking markedly prolonged.