Cardiology

Corrected QT (QTc, Bazett)

Heart-rate-corrected QT interval.

Education and reference only. Not a substitute for clinical judgement, local policy or product labelling. Always verify before clinical use. Values are calculated in your browser and never stored.

When to use

Use to correct the measured QT interval for heart rate, e.g. when assessing drug-induced QT prolongation.

Why use

The QT interval varies with rate; QTc allows comparison and risk assessment.

Critical actions

Bazett over-corrects at high heart rates and under-corrects at low rates. Thresholds differ by sex (≈>450 ms men, >470 ms women). Interpret with the ECG and medications.

Evidence & references

Bazett HC. An analysis of the time-relations of electrocardiograms. Heart. 1920.

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