Zeppenfeld K, Tfelt-Hansen J, de Riva M, Winkel BG, Behr ER, Blom NA, Charron P, Corrado D, Dagres N, de Chillou C, Eckardt L, Friede T, Haugaa KH, Hocini M, Lambiase PD, Marijon E, Merino JL, Peichl P, Priori SG, Reichlin T, Schulz-Menger J, Sticherling C, Tzeis S, Verstrael A, Volterrani M; ESC Scientific Document Group. 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. Eur Heart J. 2022 Oct 21;43(40):3997-4126. doi: 10.1093/eurheartj/ehac262.

Priori SG, Wilde AA, Horie M, Cho Y, Behr ER, Berul C, Blom N, Brugada J, Chiang CE, Huikuri H, Kannankeril P, Krahn A, Leenhardt A, Moss A, Schwartz PJ, Shimizu W, Tomaselli G, Tracy C. HRS/EHRA/APHRS expert consensus statement on the diagnosis and management of patients with inherited primary arrhythmia syndromes: document endorsed by HRS, EHRA, and APHRS in May 2013 and by ACCF, AHA, PACES, and AEPC in June 2013. Heart Rhythm. 2013 Dec;10(12):1932-63. doi: 10.1016/j.hrthm.2013.05.014.

Taran LM, Szilagyi N. The duration of the electrical systole, Q-T, in acute rheumatic carditis in children. Am Heart J. 1947 Jan;33(1):14-26. doi: 10.1016/0002-8703(47)90421-3.

Bazett HC. An analysis of the time-relations of electrocardiograms. Heart 1920; (7): 353–37.

Fridericia LS. The duration of systole in an electrocardiogram in normal humans and in patients with heart disease. 1920. Ann Noninvasive Electrocardiol. 2003;8(4):343-51.

Hodges MS, Salerno D, Erlinen D. Bazett's QT correction reviewed: evidence that a linear QT correction for heart rate is better. J Am Coll Cardiol. 1983;1:694.

Sagie A, Larson MG, Goldberg RJ, Bengston JR, Levy D. An improved method for adjusting the QT interval for heart rate (the Framingham Heart Study) The American Journal of Cardiology 1992; 70; 797-801.

Rautaharju PM, Mason JW, Akiyama T. New age- and sex-specific criteria for QT prolongation based on rate correction formulas that minimize bias at the upper normal limits. Int J Cardiol. 2014;174(3):535-540.

Cobos Gil MA, García Rubira JC. Who was the creator of Bazett's formula? Rev Esp Cardiol. 2008 Aug;61(8):896-7.

Patel PJ, Borovskiy Y, Killian A, Verdino RJ, Epstein AE, Callans DJ, Marchlinski FE, Deo R. Optimal QT interval correction formula in sinus tachycardia for identifying cardiovascular and mortality risk: Findings from the Penn Atrial Fibrillation Free study. Heart Rhythm. 2016 Feb;13(2):527-35. doi: 10.1016/j.hrthm.2015.11.008.

Tian WB, Zhang WS, Jiang CQ, Liu XY, Zhu F, Jin YL, Zhu T, Lam TH, Cheng KK, Xu L. Optimal QT Correction Formula for Older Chinese: Guangzhou Biobank Cohort Study. Cardiology. 2024 Oct 30:1-12. doi: 10.1159/000542238.

Yazdanpanah MH, Naghizadeh MM, Sayyadipoor S, Farjam M. The best QT correction formula in a non-hospitalized population: the Fasa PERSIAN cohort study. BMC Cardiovasc Disord. 2022 Feb 16;22(1):52. doi: 10.1186/s12872-022-02502-2.

Dahlberg P, Diamant UB, Gilljam T, Rydberg A, Bergfeldt L. QT correction using Bazett's formula remains preferable in long QT syndrome type 1 and 2. Ann Noninvasive Electrocardiol. 2021 Jan;26(1):e12804. doi: 10.1111/anec.12804.

Mahendran S, Gupta I, Davis J, Davis AJ, Orchard JW, Orchard JJ. Comparison of methods for correcting QT interval in athletes and young people: A systematic review. Clin Cardiol. 2023 Sep;46(9):1106-1115. doi: 10.1002/clc.24093

Vandenberk B, Vandael E, Robyns T, et al. Which QT Correction Formulae to Use for QT Monitoring?. J Am Heart Assoc. 2016;5(6).

Extramiana F, Maury P, Maison-Blanche P, Duparc A, Delay M, Leenhardt A. Electrocardiographic biomarkers of ventricular repolarisation in a single family of short QT syndrome and the role of the Bazett correction formula. Am J Cardiol. 2008 Mar 15;101(6):855-60. doi: 10.1016/j.amjcard.2007.10.049.

Vandenberk B, Vandael E, Robyns T, Vandenberghe J, Garweg C, Foulon V, Ector J, Willems R. QT correction across the heart rate spectrum, in atrial fibrillation and ventricular conduction defects. Pacing Clin Electrophysiol. 2018 Sep;41(9):1101-1108. doi: 10.1111/pace.13423.

Phan DQ, Silka MJ, Lan YT, Chang RK. Comparison of formulas for calculation of the corrected QT interval in infants and young children. J Pediatr. 2015 Apr;166(4):960-4.e1-2. doi: 10.1016/j.jpeds.2014.12.037.

Chan A, Isbister GK, Kirkpatrick CMJ, Dufful SB. Drug-induced QT prolongation and torsades de pointes: evaluation of a QT nomogram. QJM. 2007;100(10):609-615.

Othong R, Wattanasansomboon S, Kruutsaha T, Chesson D, Arj-Ong Vallibhakara S, Kazzi Z. Utility of QT interval corrected by Rautaharju method to predict drug-induced torsade de pointes. Clin Toxicol (Phila). 2019;57(4):234-239.

Indik JH, Pearson EC, Fried K, Woosley RL. Bazett and Fridericia QT correction formulas interfere with measurement of drug-induced changes in QT interval. Heart Rhythm. 2006 Sep;3(9):1003-7. doi: 10.1016/j.hrthm.2006.05.023.

Luo S, Michler K, Johnston P, Macfarlane PW. A comparison of commonly used QT correction formulae: the effect of heart rate on the QTc of normal ECGs. J Electrocardiol. 2004;37 Suppl:81-90. doi: 10.1016/j.jelectrocard.2004.08.030.

Dr. Alex Sagie

Dr. Louis S. Fridericia

Dr. Henry Cuthbert Bazett

Corrected QT Interval (QTc)

formula

heart_rate

speed

qt_interval

qt_interval2

Corrects the QT interval for heart rate extremes (choose from Bazett, Fridericia, Framingham, Hodges, or Rautaharju formulas).

Corrected QT (QTc)

The Corrected QT Interval (QTc) adjusts the QT interval correctly for heart rate extremes.

Heart Rate/Pulse

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Light's Criteria

Predicts risk for community-acquired pneumonia due to drug-resistant pathogens.

DRIP Score

Determines the degree of illness of a patient.

MEWS Score

The American Academy of Pediatrics (AAP) focuses on the health, safety, and well-being of infants, children, and young adults. With about 67,000 members, including pediatricians, medical subspecialists, and surgical specialists, the AAP supports optimal care. Over 45,000 members are board-certified Fellows of the AAP (FAAP). Its mission is to promote children's health and well-being while supporting members' professional needs.

American Academy of Pediatrics (AAP)

The American Association for Physician Leadership&reg; (AAPL) is the world&rsquo;s oldest and largest professional association dedicated solely to maximizing physician leadership.&nbsp;From the moment physicians begin their leadership journey through the time they are seasoned leaders, AAPL provides education and training, resources and tools, and content and experiences needed to close gaps between hands-on clinical care, organization system improvements and optimized business outcomes.

American Association for Physician Leadership (AAPL)

American Association for the Study of Liver Diseases

The American College of Emergency Physicians (ACEP) represents more than 38,000 emergency physicians, emergency medicine residents and medical students. ACEP promotes the highest quality of emergency care and is the leading advocate for emergency physicians and their patients, and the public. Members may earn up to 850 continuing medical education hours every year through ACEP&rsquo;s robust catalog of peer-reviewed publications and on-demand courses presented by world-renowned emergency medicine experts.

American College Of Emergency Physicians

The American College of Gastroenterology (ACG) supports clinicians in delivering high-quality, evidence-based care to gastroenterology patients. Its mission is to advance care for those with gastrointestinal disorders through excellence, innovation, and advocacy. ACG provides members with up-to-date scientific information through annual meetings, the American Journal of Gastroenterology, training courses, and research grants, focusing on digestive health and GI disorder treatments.

American College of Gastroenterology

American College of Rheumatology

The American Gastroenterological Association (AGA), founded in 1897, provides leadership and education to over 16,000 members worldwide, all dedicated to advancing gastroenterology. The AGA&rsquo;s mission is to empower clinicians and researchers to improve digestive health through clinical guidance, practice resources, and peer-reviewed research. Key journals include Gastroenterology, Clinical Gastroenterology and Hepatology, Cellular and Molecular Gastroenterology and Hepatology, and others.

American Gastroenterological Association

American Heart Association

American Urological Association

EB Medicine is the premier provider of evidence-based clinical content and CME resources for emergency medicine practitioners.

EB Medicine

MDCalc CME

Postgraduate Institute for Medicine

The Rome Foundation is a nonprofit organization dedicated to advancing the diagnosis and treatment of Disorders of Gut-Brain Interaction (DGBI), also known as functional gastrointestinal disorders. Its mission is to improve the lives of people with DGBI. For over 30 years, the Rome Foundation has worked with scientists and clinicians worldwide to classify and assess GI function and dysfunction, creating symptom-based criteria used in clinical trials and daily practice to guide diagnosis and treatment.

The ROME Foundation

Listen to the VACO co-creators break down how to use VACO\, what it does\, and what it doesn’t.

Calc Function