Cardiology

QTc (Bazett and Fridericia)

Correct the QT interval for heart rate before prescribing QT-prolonging drugs.

Version Bazett 1920 / Fridericia 1920

Inputs

Measured QT interval(ms)

Heart rate(/min)

QTc Bazett (ms)

432

Within normal limits; safe to proceed with usual caution.

Fridericia QTc 421 ms
Bazett over-corrects at high rates and under-corrects at low rates.

Formula

QTc(Bazett) = QT / √RR; QTc(Fridericia) = QT / RR^(1/3); RR in seconds = 60/heart rate

Heart · 1920

Demo content. Educational decision support only. Verify every dose, citation and recommendation against your national formulary and the primary source before clinical use.