QTc (Framingham / Hodges)
Heart-rate-corrected QT with the linear Framingham or Hodges formula
Sources last checked: 2026-11-03
QTc (Framingham / Hodges)
Heart-rate-corrected QT with the linear Framingham or Hodges formula
Linear corrections are less rate-dependent than Bazett, but most normal limits and drug-safety thresholds were set with Bazett or Fridericia; report which formula was used. Bands are not sex-adjusted automatically (< 450 ms men, < 460 ms women).
Interpretation
| < 450 ms — normal | Below the upper limit of normal for both sexes (same limits as the Bazett/Fridericia QTc calculator: prolonged ≥ 450 ms in men, ≥ 460 ms in women). |
|---|---|
| 450–459 ms | Prolonged in men; still within normal limits in women. |
| 460–479 ms — prolonged | Prolonged in both sexes. Common causes include QT-prolonging drugs, hypokalaemia, hypomagnesaemia and hypocalcaemia. |
| 480–500 ms | Reaches the ESC 2022 threshold for diagnosing long-QT syndrome (QTc ≥ 480 ms on repeated 12-lead ECGs, after excluding secondary causes). |
| > 500 ms — high risk | Markedly prolonged with a substantially higher risk of torsade de pointes; the thresholds were largely established with Bazett/Fridericia. |
What is the QTc (Framingham / Hodges)?
Framingham and Hodges are linear QT corrections that add or subtract a fixed amount per unit of heart rate instead of dividing by a root of RR. Sagie et al. derived the Framingham formula from 5,018 participants of the Framingham Heart Study (1992); Hodges et al. proposed their heart-rate-based correction in 1983. Both are less rate-dependent than Bazett at high and low heart rates.
When to use it
- Tachycardia or bradycardia, where Bazett over- or under-corrects
- Cross-checking a borderline QTc obtained with Bazett
- Research or protocols that specify a linear correction
When not to use it
- Irregular rhythms without averaging several beats
- Bundle branch block or paced rhythm without a QRS-adjusted approach
- Comparison with thresholds established using a different formula, without noting the formula
How it is calculated
RR (s) = 60 / HR Framingham: QTc = QT + 154 × (1 − RR) Hodges: QTc = QT + 1.75 × (HR − 60)
Clinical pearls and limitations
- Linear corrections are less rate-dependent than Bazett, but most normal limits and drug-safety thresholds were set with Bazett or Fridericia; report which formula was used. Bands are not sex-adjusted automatically (< 450 ms men, < 460 ms women).
- At 60/min (RR = 1 s) all four corrections give QTc = QT.
- The Framingham constant is 0.154 s, i.e. 154 ms; enter QT in milliseconds.
- Always document the correction used — the same ECG can be 'normal' with one formula and 'prolonged' with another.
- QT should be measured manually in the lead with the longest QT, ideally II or V5.
Frequently asked questions
What is the Framingham QTc formula?
QTc = QT + 0.154 × (1 − RR) with QT and RR in seconds, i.e. QT (ms) + 154 × (1 − RR).
What is the Hodges formula?
QTc = QT (ms) + 1.75 × (heart rate − 60).
Which QTc formula is best?
None is perfect; Fridericia and linear formulas such as Framingham are less rate-dependent than Bazett. Use one consistently and record which.
Evidence and guidelines
- Primary source: Sagie A, Larson MG, Goldberg RJ, Bengtson JR, Levy D. An improved method for adjusting the QT interval for heart rate (the Framingham Heart Study). Am J Cardiol 1992;70(7):797-801; Hodges M, Salerno D, Erlien D. Bazett's QT correction reviewed: evidence that a linear QT correction for heart rate is better. J Am Coll Cardiol 1983;1:694 (abstract).
- Multidimensional performance evaluation of QTc formulas (Bazett, Fridericia, Framingham, Hodges, Rautaharju, Dmitrienko) in 3258 healthy young adults. J Am Heart Assoc 2026;15(7):e046279 (states the Hodges formula).
- Zeppenfeld K et al. 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. Eur Heart J 2022;43:3997-4126.
- Rautaharju PM et al. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram, part IV. Circulation 2009;119:e241-e250.
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