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Cited by 454Cardiac electrophysiology and arrhythmiasECG Monitoring and AnalysisHeart Rate Variability and Autonomic Control

A comparison of commonly used QT correction formulae: The effect of heart rate on the QTc of normal ECGs

Luo, Shen, Michler, Kurt, Johnston, Paul, Macfarlane, Peter W.·2004·Journal of Electrocardiology
DOI 10.1016/j.jelectrocard.2004.08.030
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Abstract

The corrected QT interval (QTc) is widely used in pharmaceutical studies and clinical practice. Bazett's QT correction formula is still the most popular, despite Simonson's warning in 1961 that it could not be recommended. Other QTc formulae, e.g. Fridericia, Framingham, and Hodges, are also used. This study compares these four formulae using 10,303 normal ECGs recorded from four US hospitals. QT intervals were measured by the same computer program on ECGs confirmed by physicians. The distributions of QTc based on Fridericia, Framingham, and Hodges formulae were similar but Bazett's was significantly wider. The global group QTc-heart rate (HR) correlation coefficients were calculated as Bazett 0.33, Fridericia 0.24, Framingham 0.26, and Hodges 0.11, with the uncorrected QT-HR correlation being 0.82. Overall by far, Hodges QTc is significantly less correlated with HR compared to the others. Certain subgroup correlations of gender and low, mid, or high HR show that one individual formula can out-perform the others, whereby automated selection of QT correction formula based on the patient's HR and gender could be implemented as another option in products. The upper normal limits of corrected QTc were determined by excluding the top 2% from the global distribution charts as follows: Bazett 483 ms, Fridericia 460 ms, Framingham 457 ms, and Hodges 457 ms. Whether for males and/or females, the middle range of HR from 60 to 99 bpm has similar upper normal limits of QTc for all formulae except Bazett. Numerous references recommend 420 to 440 ms as the threshold for reporting prolonged QTc when using Bazett's formula. Based on this database, 30% of apparently normal ECGs would be reported as having abnormal QT intervals for the 440 ms threshold, or 10% if 460 ms is chosen, compared to <2% for the other formulae. It was also noted that QT has a linear trend with HR but not with RR.

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  • Measurement of the QTc interval is not without difficulties, and at least six alternative methods of rate correction are available.

    “Finally, it should be noted that measurement of the QTc interval is not without difficulties, and at least six alternative methods of rate correction are available [83, 149].”

    From European guidelines on managing adverse effects of medication for ADHD (2011) · cites this paper as [83]

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Authors
Luo, S., Michler, K., Johnston, P., & Macfarlane, P. W.
Affiliations
University of Glasgow (GB)
Corresponding author
Luo, Shen
ORCID
Macfarlane, Peter W.
Venue
Journal of Electrocardiology
Publisher
Elsevier BV
Published
2004-10
Volume
37
Pages
81-90
ISSN
0022-0736 (ISSN-L)
DOI
10.1016/j.jelectrocard.2004.08.030
OpenAlex
W2005426535
Cited by
454
References
23
Citations by year
2026: 19 · 2025: 11 · 2024: 21 · 2023: 18 · 2022: 27 · 2021: 32 · 2020: 31 · 2019: 30 · 2018: 27 · 2017: 29 · 2016: 22 · 2015: 18 · 2014: 29 · 2013: 16 · 2012: 23
FWCI
6.10
Type
journal article
Language
en
Open access
closed
Licence
Locations
  • Journal of Electrocardiology (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Cardiac electrophysiology and arrhythmias
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › ECG Monitoring and Analysis
  • Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Heart Rate Variability and Autonomic Control
Keywords
Bazett formula, Fridericia formula, Framingham formula, Hodges formula, heart rate, QT interval, normal ECG, gender differences
MeSH terms
Adolescent, Adult, Aged, Aged, 80 and over, Algorithms, Bradycardia, Electrocardiography, Female, Heart Rate, Humans, Male, Middle Aged, Sex Factors, Signal Processing, Computer-Assisted, Sinoatrial Node, Software, Tachycardia, Sinus, Linear Models, Nonlinear Dynamics

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