QTc for QT 420 ms at Bradycardia 50 bpm
A QT of 420 ms at 50 bpm yields a QTc of approximately 384 ms, which falls within the normal range.
How to use this tool
- Enter the measured QT interval in milliseconds.
- Enter the heart rate in beats per minute.
- Select sex to apply the matching prolonged-QTc threshold.
- Read the corrected QT (QTc) and its interpretation.
Determine QTc when bradycardia (50 bpm) artificially lengthens the raw QT interval to 420 ms.
Frequently asked questions
- What QTc is considered prolonged?
- Commonly cited upper limits are about 450 ms for men and 470 ms for women; a QTc above 500 ms is generally regarded as markedly prolonged and higher risk. Thresholds vary by source.
- Why correct the QT for heart rate at all?
- The raw QT naturally shortens as heart rate increases, so without correction you cannot tell whether a short QT reflects a fast heart rate or a genuinely short interval.
- Is Bazett's formula the best correction?
- It is the most common but not always the most accurate. At very fast or very slow heart rates, formulas such as Fridericia or Framingham track the true QTc more closely.