The DOI matches its Crossref record, with a small difference in title or year; 47 of the 49 references it cites were found in a registry or an index.
Diurnal pattern of QTc interval: How long is prolonged?
Open accessAbstract
Objectives This study sought to evaluate the range and variability of the QT and corrected QT (QTc) intervals over 24 h and to assess their pattern and relation to heart rate variability.Background Recent Holter monitoring data have revealed a high degree of daily variability in the QTc interval. The pattern of this variability and its relation to heart rate variability remain poorly characterized.Methods We developed and validated a new method for continuous measurement of QT intervals from three-channel, 24-h Holter recordings. Average RR, QT, QTc and heart rate variability were measured from 5-min segments of data from 21 healthy subjects.Results Measurement of 6,048 segments showed mean (+/- SD) RR, QT and QTc intervals of 830 +/- 100, 407 +/- 23 and 445 +/- 16 ms, respectively (mean QTc interval for men 434 +/- 12 ms, 457 +/- 10 ms for women, p < 0.0001). The average maximal QTc interval was 495 +/- 21 ms and the average QTc range 95 +/- 20 ms. The maximal QTc interval was > or = 500 ms in 6 subjects and > or = 490 ms in 13. The 95% upper confidence limit for the mean 24-h QTc interval was 452 ms (men 439 ms, women 461 ms). The RR, QT and QTc intervals and the high frequency component of heart rate variability were greater during sleep. Both the QTc interval and the variability between hourly minimal and maximal QTc intervals reached their circadian peak shortly after awakening, before declining to daytime levels.Conclusions The maximal QTc interval over 24 h in normal subjects is longer than heretofore thought. Both QT and QTc intervals are longer during sleep. The QTc interval and QTc variability reach a peak shortly after awakening, which may reflect increased autonomic instability during early waking hours, and the time of the peak value corresponds in time to the period of reported increased vulnerability to ventricular tachycardia and sudden cardiac death. These findings have implications regarding the definition of QT prolongation and its use in predicting arrhythmias and sudden death.
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Cites
STATISTICAL METHODS FOR ASSESSING AGREEMENT BETWEEN TWO METHODS OF CLINICAL MEASUREMENT
Martin Bland, J., & Altman, D. (1986) · The Lancet · doi:10.1016/s0140-6736(86)90837-8 · Cited by 47,965
Beckett, A. H., Rowland, M., & TURNER, P. (1965) · The Lancet · doi:10.1016/s0140-6736(65)91037-8 · Cited by 16,917
Cardiovascular neural regulation explored in the frequency domain.
Malliani, A., Pagani, M., Lombardi, F., & Cerutti, S. (1991) · Circulation · doi:10.1161/01.cir.84.2.482 · Cited by 3,569
Cardiovascular Survey Methods.
Rose, G., & Blackburn, H. (1968) · Annals of Internal Medicine · doi:10.7326/0003-4819-69-6-1335_2 · Cited by 3,090
Circadian variation and triggers of onset of acute cardiovascular disease.
Muller, J. E., Tofler, G. H., & Stone, P. H. (1989) · Circulation · doi:10.1161/01.cir.79.4.733 · Cited by 1,426
Schwartz, P. J., Periti, M., & Malliani, A. (1975) · American Heart Journal · doi:10.1016/0002-8703(75)90089-7 · Cited by 906
QT interval prolongation as predictor of sudden death in patients with myocardial infarction.
Schwartz, P. J., & Wolf, S. (1978) · Circulation · doi:10.1161/01.cir.57.6.1074 · Cited by 760
An improved method for adjusting the QT interval for heart rate (the Framingham Heart Study)
Sagie, A., Larson, M. G., Goldberg, R. J., Bengtson, J. R., & Levy, D. A. (1992) · The American Journal of Cardiology · doi:10.1016/0002-9149(92)90562-d · Cited by 715
Sex differences in the evolution of the electrocardiographic QT interval with age.
Rautaharju, P. M., Sh, Z., Wong, S., Hp, C., Berenson, G. S., Prineas, R., & Davignon, A. (1992) · PubMed · Cited by 635
QT interval prolongation predicts cardiovascular mortality in an apparently healthy population.
Schouten, E. G., Dekker, J. M., Meppelink, P., Kok, F. J., Vandenbroucke, J. P., & Pool, J. (1991) · Circulation · doi:10.1161/01.cir.84.4.1516 · Cited by 632
Research works printed but not linked: 5
- Lepeschkin, 1951, Vol. 1, 180
- Bazett, 1920, An analysis of time-relations of the electrocardiogram, Heart, 7, 353
- Hegglin, 1937, Die Klinische Bedeutung des VerlangerterDistanz (Systolendauer) in Electrokardiogram, Z Klin Med, 132, 1
- Molnar, 1995, Why not Bazett's?, PACE, 18, 852
- 1988, Vol. 3, 1531
Cited by
Sorted by citations
AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram
Surawicz, B., Childers, R., Deal, B. J., & Gettes, L. S. (2009) · Journal of the American College of Cardiology · doi:10.1016/j.jacc.2008.12.013 · Cited by 2,053
AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram
Rautaharju, P. M., Surawicz, B., & Gettes, L. S. (2009) · Journal of the American College of Cardiology · doi:10.1016/j.jacc.2008.12.014 · Cited by 1,019
Sex differences in healthy human heart rate variability: A meta-analysis
Koenig, J., & Thayer, J. F. (2016) · Neuroscience & Biobehavioral Reviews · doi:10.1016/j.neubiorev.2016.03.007 · Cited by 860
Prolonged QTc Interval and Risk of Sudden Cardiac Death in a Population of Older Adults
Straus, S. M. J. M., Kors, J. A., De Bruin, M. L., van der Hooft, C. S., Hofman, A., Heeringa, J., Deckers, J. W., Kingma, J. H., Sturkenboom, M. C. J. M., Stricker, B. H. C., et al. (2006) · Journal of the American College of Cardiology · doi:10.1016/j.jacc.2005.08.067 · Cited by 833
What Clinicians Should Know About the QT Interval
Al‐Khatib, S. M., LaPointe, N. M. A., Kramer, J. M., & Califf, R. M. (2003) · JAMA · doi:10.1001/jama.289.16.2120 · Cited by 671
Metadata
- Authors
- Molnar, J., Zhang, F., Weiss, J., Ehlert, F. A., & Rosenthal, J. E.
- Affiliations
- Northwestern University (US)
- Corresponding author
- Rosenthal, James E.
- ORCID
- Ehlert, Frederick A.
- Venue
- Journal of the American College of Cardiology
- Publisher
- Elsevier BV
- Published
- 1996-01
- Volume
- 27
- Issue
- 1
- Pages
- 76-83
- ISSN
- 0735-1097 (ISSN-L)
- OpenAlex
- W160020775
- Cited by
- 312
- References
- 49
- Citations by year
- 2026: 3 · 2025: 5 · 2024: 4 · 2023: 6 · 2022: 3 · 2021: 8 · 2020: 6 · 2019: 4 · 2018: 8 · 2017: 12 · 2016: 5 · 2015: 8 · 2014: 17 · 2013: 18 · 2012: 11
- FWCI
- 12.44
- Type
- journal article
- Language
- en
- Open access
- bronze
- doi.org
- Licence
- Locations
- Journal of the American College of Cardiology (publishedVersion)
- PubMed (publishedVersion)
- Topics
- Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Cardiac electrophysiology and arrhythmias
- Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › Heart Rate Variability and Autonomic Control
- Health Sciences › Medicine › Cardiology and Cardiovascular Medicine › ECG Monitoring and Analysis
- Keywords
- QTc interval, diurnal variation, circadian rhythm, heart rate variability, QT prolongation, sleep, awakening, autonomic instability, sudden cardiac death, ventricular tachycardia, Holter monitoring, QT interval measurement
- MeSH terms
- Adult, Aged, Circadian Rhythm, Diagnosis, Computer-Assisted, Female, Heart Conduction System, Heart Rate, Humans, Male, Middle Aged, Reference Values, Reproducibility of Results, Observer Variation, Electrocardiography, Ambulatory, Linear Models, Least-Squares Analysis, Sex Distribution
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