KW - Pacemaker A New Formula for Estimating the True QT Interval in Left Bundle Branch Block. In the case of pacemaker stimulation, the Bogossian formula was additionally applied (31). The https:// ensures that you are connecting to the The https:// ensures that you are connecting to the Epub 2014 Aug 19. Left bundle branch potential predicts better electrical synchrony in bradycardia patients receiving left bundle branch pacing. 2020) beschrieben. The QTmc interval was calculated with the Bazett formula, and this was compared with the QTc interval during intrinsic rhythm. Application of the Bogossian formula for evaluation of the QT interval in pacemaker patients with stimulated left bundle branch block. Die Bogossian-Formel ist eine alltagstaugliche Methode, die mutmalich wahre Dauer der Repolarisation im EKG mit verbreiterten Kammerkomplexen zu ermitteln. Circ J 75(7):16091615 CrossRef, Zurck zum Zitat Pang BJ, Kumar S, Tacey MA, Mond HG (2014) Capturing the His-Purkinje system is not possible from conventional right ventricular apical and nonapical pacing sites. Upper limit of normal is usually defined as 440 msec. Twelve-lead ECG recordings were obtained during both intrinsic rhythm and RV pacing with induced LBBB. Careers. International journal of cardiology. Int J Cardiol Heart Vasc. JT interval; QT formula; QT interval; QT prolongation; left bundle brunch block; long QT. Part of Springer Nature. QRSb = gemessene QRS-Breite. Tablot et al. Applicability of a Novel Formula (Bogossian formula) for Evaluation of the QTInterval in Heart Failure and Left Bundle Branch Block Due to Right Ventricular Pacing GERRIT FROMMEYER Corresponding Author gerrit.frommeyer@ukmuenster.de Division of Electryophysiology, Department of Cardiovascular Medicine, University of Mnster, Mnster, Germany We thank Inga Bayh and Prof. Dr. Frank Krummenauer (Institute for Medical Biometry and Epidemiology, School of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany) for statistical advice. Int J Cardiol Heart Vasc. Disclaimer. 8600 Rockville Pike Weipert, K.F., Bogossian, H., Conzen, P. et al. Am J Cardiol 93(8):10171021 CrossRef, Zurck zum Zitat Chakravarty S, Kluger J, Chhabra L, Ramu B, Coleman C (2015) Corrected QT in ventricular paced rhythms: what is the validation for commonly practiced assumptions? Bogossian H, Frommeyer G, Ninios I, Hasan F, Nguyen QS, Karosiene Z, Mijic D, Kloppe A, Suleiman H, Bandorski D, Seyfarth M, Lemke B, Eckardt L, Zarse M. Heart Rhythm. National Library of Medicine Seeing through the maze of complete left bundle branch block. doi: 10.1111/anec.12475. Epub 2017 Jun 7. Heart Rhythm 11(12):22732277 CrossRef, Zurck zum Zitat Bogossian H, Frommeyer G, Ninios I, Hasan EP F, et al. Conclusion: The Bogossian formula is a reliable tool for QTc interval evaluation in pacemaker patients with LBBB due to apical or non-apical RV pacing. Learn more about Institutional subscriptions, Woosley RL, Romero K (2013) Assessing cardiovascular drug safety for clinical decision-making. Therefore, the Bogossian formula seems to be a simple and investigator-friendly method to correct BBB and to facilitate the determination of QTc interval, not only in patients with LBBB as previously reported, but also in RBBB with or without additional block of one of the left ventricular fascicles. Die Formel hat Bogossian 2014 erstmals fr Patienten mit LSB vorgestellt (Bogossian et al. The Bogossian formula is a reliable tool for QTc interval evaluation in pacemaker patients with LBBB due to apical or non-apical RV pacing and preserved left ventricular function. Would you like email updates of new search results? Bethesda, MD 20894, Web Policies Background: The evaluation of the QT interval in the presence of left bundle branch block (LBBB) is associated with the challenge to discriminate native QT interval from the prolongation due to the increase in QRS duration. MeSH . PMC e.g. FOIA QTb = gemessene QT-Zeit A new experimentally validated formula to calculate the QT interval in the presence of left bundle branch block holds true in the clinical setting . Application of the Bogossian formula for evaluation of the QT interval in pacemaker patients with stimulated left bundle branch block. Bookshelf Accessibility -. However, an overestimation of 30 ms. Heart Rhythm 5(7):10151018, Nielsen JB, Graff C, Rasmussen PV, Pietersen A, Lind B et al (2014) Risk prediction of cardiovascular death based on the QTc interval: evaluating age and gender differences in a large primary care population. Bethesda, MD 20894, Web Policies Ann Noninvasive Electrocardiol. AU - Eckardt,L, volume107,pages 10331039 (2018)Cite this article. If you log out, you will be required to enter your username and password the next time you visit. Bethesda, MD 20894, Web Policies The presence of left bundle branch block (LBBB) represents a particular challenge in properly measuring the QT interval. Click here for full notice and disclaimer. Department of Cardiology and Angiology, Medical Clinic I, University Clinic of Gieen, Gieen, Germany. 2017 Apr;40(4):409-416. doi: 10.1111/pace.13027. G Ital Cardiol (Rome). Pacemaker and AQUA Institute for Applied Quality Improvement and Research in Health Care GmbH workgroup. Abitabile Beccia Brin Carusone Cinone Colantuoni Del Core Gj Marianna Domenico Chiara Caterina Francesca Sara M. Arrhythmias are associated with aging, coronary artery disease, subtle myocardial injury, hyperinflammatory status, coagulative unbalance, and prolonged QTc dispersion in patients with COVID-19, and confer a worse in-hospital prognosis. Frommeyer G, Bogossian H, Pechlivanidou E, Conzen P, Gemein C, Weipert K, Helmig I, Chasan R, Johnson V, Eckardt L, Hamm CW, Seyfarth M, Lemke B, Zarse M, Schmitt J, Erkapic D. Pacing Clin Electrophysiol. The most commonly used QT correction is that of Bazett which was proposed in 1920. Disclaimer. The ECG pattern of high-grade LAD stenosis has proven to be an important marker ofhigh-risk patients with chest pain and may also be seen in patients with a right ventricular pacemaker on resumption of native QRS conduction. Pacing Clin Electrophysiol 37(6):724730. Ann Noninvasive Electrocardiol. The QT interval measured during LBBB was corrected using the Bogossian formula to obtain the modified QT (QTm). Epub 2021 Feb 13. This QTc calculator is designed to show the QT corrected interval for heart rate extremes because it returns the estimations by 4 different equations as presented below: QT corrected interval: by Bazett's formula: QTc = QT/ (RR in seconds) by Fridericia's formula: QTc = QT/ (RR^0.33) by Framingham's formula: QTc = QT + 0.154 (1-RR) JO - Clin Res Cardiol Eighty-three patients (789years; male. official website and that any information you provide is encrypted The purpose of this study is to validate the newest formula to evaluate QT interval in the presence of LBBB with the aim of validating the abovementioned formula in the clinical setting. However, an overestimation of 30ms should be included in the calculation. The Bogossian formula showed a significant deviation from the actual QTc interval with both the Bazett and the Fridericia formulas. J Card Fail 18(12):939949 CrossRef, Zurck zum Zitat Vrtovec B, Ryazdanbakhsh AP, Pintar T, Collard CD, Gregoric ID, Radovancevic B (2006) QTc interval prolongation predicts postoperative mortality in heart failure patients undergoing surgical revascularization. Click here for full notice and disclaimer. Eur Heart J 35(20):13351344, Priori SG, Schwartz PJ, Napolitano C, Bloise R, Ronchetti E et al (2003) Risk stratification in the long-QT syndrome. Unfortunately the Bazett correction overcorrects with heart rates >110 bpm and undercorrects with heart rates <60 bpm. Bei LSB, RSB und rechtsventrikulrer Schrittmacher-Stimulation sind die sonst blichen Grenzwerte fr die QT-Zeit deshalb nicht geeignet, die Arrhythmiegefhrdung betroffener Patienten abzuschtzen. Epub 2014 Aug 19. A total of 163 patients with a cardiac one- or two-chamber pacemaker were included in this prospective, multicentre observational study. Epub 2017 Apr 18. A more precise formula was developed and described by Rautaharju et al. A novel and practical method that might facilitate discrimination between patients with apparent L BBB and true LBBB by comparing Q-LV/QRS ratios during intrinsic activation and during RV stimulation is presented. 2.QT Interval? An official website of the United States government. Application of the Bogossian formula for evaluation of the QT interval in pacemaker patients with stimulated left bundle branch block. Bestellen Sie unseren Fach-Newsletter und bleiben Sie gut informiert ganz bequem per eMail. 2014 Dec;11(12):2273-7. doi: 10.1016/j.hrthm.2014.08.026. This review will report the safety of FLT3 inhibitors that are registered for acute myeloid leukemia induction and rescue therapy and suggest strategies to mitigate adverse events. In der Vergangenheit wurden diverse Methoden zur Berechnung der vermeintlich wahren QT-Zeit vorgeschlagen. Frommeyer G, Bogossian H, Pechlivanidou E, Conzen P, Gemein C, Weipert K, Helmig I, Chasan R, Johnson V, Eckardt L, Hamm CW, Seyfarth M, Lemke B, Zarse M, Schmitt J, Erkapic D. Pacing Clin Electrophysiol. Bogossian H, Linz D, Heijman J, Bimpong-Buta NY, Bandorski D, Frommeyer G, Erkapic D, Seyfarth M, Zarse M, Crijns HJ. Here we demonstrate the applicability of the Bogossian formula in pacemaker patients with LBBB due to apical or nonapical right ventricular (RV) pacing and preserved left ventricular function. 2018 May-Jun;51(3):481-486. doi: 10.1016/j.jelectrocard.2017.12.039. Up to now, there is no clear, View 5 excerpts, references background and methods, Journal of Interventional Cardiac Electrophysiology. Bitte aktivieren Sie Java-Script in Ihrem Browser, damit Sie alle Vorteile und Funktionen dieser Website nutzen knnen. MeSH Heart Rhythm 5(7):10151018 CrossRef, Zurck zum Zitat Nielsen JB, Graff C, Rasmussen PV, Pietersen A, Lind B et al (2014) Risk prediction of cardiovascular death based on the QTc interval: evaluating age and gender differences in a large primary care population. However, an overestimation of 30 ms should be included in the calculation. Calculate the corrected QT interval Questions 1.QT Correction? 2018 Nov;107(11):1033-1039. doi: 10.1007/s00392-018-1275-6. National Library of Medicine https://doi.org/10.1007/s00392-018-1275-6, DOI: https://doi.org/10.1007/s00392-018-1275-6. An official website of the United States government. Alex Saige, MD, is a cardiologist at the Edith Wolfson Medical Center in Israel. government site. The Bogossian formula showed a significant deviation from the actual QTc interval with both the Bazett and the Fridericia formulas. The QTc interval was determined to be 461 34 ms (modified by Bogossian's formula) in paced and 436 34 ms in intrinsic rhythm. The evaluation of the QT interval in the presence of left bundle branch block (LBBB) is associated with the challenge to discriminate native QT interval from the prolongation due to the increase in QRS duration. Eighty-three patients (78 9 years; male n = 83) with apical and eighty patients (71 13 years; male n = 80) with non-apical RV pacing were included in this study. Department of Cardiology, Diakonie Jung-Stilling Hospital, Wichernstrasse 40, 57074, Siegen, Germany. The newest formula to evaluate QT interval in the presence of LBBB suggests: modified QT during LBBB = measured QT interval minus 50% of LBBB duration. View 7 excerpts, references methods and background, Journal of the American College of Cardiology. Completing the square method is a technique for find the solutions of a quadratic equation of the form ax^2 + bx + c = 0. Methods: Here we demonstrate the applicability of the "Bogossian formula" in pacemaker patients with LBBB due to apical or nonapical right ventricular (RV) pacing and preserved left ventricular function. View 2 excerpts, references background and methods, Europace : European pacing, arrhythmias, and cardiac electrophysiology : journal of the working groups on cardiac pacing, arrhythmias, and cardiac cellular electrophysiology of the European Society of Cardiology. Harilaos.bogossian@klinikum-luedenscheid.de; Mrkische Kliniken GmbH, Department of Cardiology and Angiology, Klinikum Ldenscheid, Ldenscheid, Germany. and transmitted securely. Department of Cardiology, Kerckhoff Heart and Thorax Center, Bad Nauheim, Germany. Epub 2014 Aug 19. An improved method for adjusting the QT interval for heart rate (the Framingham Heart Study). Positionspapier Digital Devices der EHRA, EKG-Weiterbildung verbessert die Infarkttherapie. International Journal of Cardiology. Epub 2018 May 11. 5%- Grenzwert bei 460 bzw. T1 - Application of the Bogossian formula for evaluation of the QT interval in pacemaker patients with stimulated left bundle branch block. All measurements were performed by an experienced electrophysiologist and a trainee who worked independently and in a blinded manner. J Card Fail 18(12):939949, Vrtovec B, Ryazdanbakhsh AP, Pintar T, Collard CD, Gregoric ID, Radovancevic B (2006) QTc interval prolongation predicts postoperative mortality in heart failure patients undergoing surgical revascularization. New Formula for Defining "Normal" and "Prolonged" QT in Patients With Bundle Branch Block - A Variant of Bogossian's Formula. Incidence and outcomes of long QTc in acute medical admissions. Disclaimer. Texas Heart Inst J 33(1):38, Zurck zum Zitat Inoue K, Okayama H, Nishimura K, Saito M, Yoshii T et al (2011) Right ventricular septal pacing preserves global left ventricular longitudinal function in comparison with apical pacing: analysis of speckle tracking echocardiography. 2020 Sep 19;30:100636. doi: 10.1016/j.ijcha.2020.100636. Erkapic D, Frommeyer G, Brettner N, Szener K, Crijns HJGM, Seyfarth M, Hamm CW, Bogossian H. Clin Cardiol. Funk MC, Cates KW, Rajagopalan A, Lane CE, Lou J. J Acad Consult Liaison Psychiatry. Unable to load your collection due to an error, Unable to load your delegates due to an error. KW - Left bundle branch block The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Zurck zum Zitat Woosley RL, Romero K (2013) Assessing cardiovascular drug safety for clinical decision-making. 2016 in press Bogossian H, Frommeyer G, Ninios I, Hasan EP F, et al. - 193.70.22.229. The authors have no conflicts of interests to disclose. JF - Clinical research in cardiology : official journal of the German Cardiac Society The acquired mean native QTc intervals and those calculated by the presented formula displayed no significant differences (p > .99 and p > .75). Background: PMC the correction formula used to correct the QT-interval for heart rate, age and/or sex, although age and sex are known modulating factors of the QTc-interval. Epub 2017 Mar 3. 26(4):399423 CrossRef, Zurck zum Zitat Markewitz A (2015) Annual report 2013 of the German Cardiac Pacemaker and Defibrillator Register, part 1Pacemaker. Pacing Clin Electrophysiol 37(6):724730 CrossRef, https://doi.org/10.1007/s00392-018-1275-6, Application of the Bogossian formula for evaluation of the QT interval in pacemaker patients with stimulated left bundle branch block | springermedizin.de. The QT interval measured during LBBB was corrected using the Bogossian formula to obtain the "modified QT" (QTm). Department of Cardiology, Helios Klinikum Wuppertal, Wuppertal, Germany. 2018 Nov;107 (11):1033-1039. doi: 10.1007/s00392-018-1275-6. Epub 2018 Jan 31. Type your tag names separated by a space and hit enter. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Clinical Research in Cardiology Careers. Epub 2020 May 19. An official website of the United States government. New formula for evaluation of the QT interval in patients with left bundle branch block. Assessment of left ventricular dyssynchrony in pacing-induced left bundle branch block compared with intrinsic left bundle branch block. 2016 Sep;27(3):307-22. doi: 10.1007/s00399-016-0439-1. ECG parameters, such as QTcH, TP and TP/QT do not helpful predicting Troponin I elevations in patients on anthracycline-based chemotherapy, and further studies based on hard endpoints, for example, clinical systolic dysfunction occurring at one year, would give better information on their utility. The https:// ensures that you are connecting to the 2014 Dec;11(12):2273-7. doi: 10.1016/j.hrthm.2014.08.026. The .gov means its official. Please enable it to take advantage of the complete set of features! After LBBB correction using the reported Bogossian formula, the QTc interval was evaluated with Bazett's formula. QTm = modifizierte QT-Zeit nach BogossianQTm = QTb 48.5 % * QRSb, QTm = modifizierte QT-Zeit sharing sensitive information, make sure youre on a federal 8600 Rockville Pike Application of the Bogossian formula for evaluation of the QT interval in pacemaker patients with stimulated left bundle branch block. An approach to the ECG in this context, and a step-by-step guide to manually measuring and correcting the QT interval, and an approach to management in common hospital-based clinical scenarios are presented. : A new experimentally . official website and that any information you provide is encrypted About The most commonly used QT correction is that of Bazett which was proposed in 1920. In this study we proved for the first time the validity and applicability of the experimentally acquired formula for the evaluation of the QT interval in the presence of LBBB in a clinical setting. AU - Lemke,B, Federal government websites often end in .gov or .mil. Schon sehr lange ist klar, dass die gemessene QT-Zeit bei Schenkelblockbildern die tatschliche Dauer der Repolarisation bersteigt. His Bundle Pacing: A New Strategy for Physiological Ventricular Activation. Int J Clin Pract. QT-Zeit und QRS-Breite knnen (natrlich nach visueller berprfung ) dem EKG-Auswertealgorithmus entnommen oder per EKG-Lineal gemessen werden. Heart & Vasculature, Annals of noninvasive electrocardiology : the official journal of the International Society for Holter and Noninvasive Electrocardiology, Inc. A practice formula to eliminate the effect of depolarization changes on QT interval in patients with R BBB is developed and allows a rapid and practical method for QT correction in RBBB in clinical practice. The mean left ventricular ejection fraction was 40 13%. The QTc interval was determined to be 461 34 ms (modified by Bogossian's formula) in paced and 436 34 ms in intrinsic rhythm. AU - Seyfarth,M, Pacing Clin Electrophysiol 40(4):409416, Frommeyer G, Milberg P, Witte P, Stypmann J, Koopmann M et al (2011) A new mechanism preventing proarrhythmia in chronic heart failure: rapid phase-III repolarization explains the low proarrhythmic potential of amiodarone in contrast to sotalol in a model of pacing-induced heart failure. 2021 Sep-Oct;62(5):501-510. doi: 10.1016/j.jaclp.2021.02.003. Google Scholar, Schneider JF, Thomas HE Jr, McNamara PM, Kannel WB (1985) Clinical-electrocardiographic correlates of newly acquired left bundle branch block: the Framingham Study. Accessibility 12 PDF Assessment of QT and JT Intervals in Patients With Left Bundle Branch Block P. Tabatabaei, Ala Keikhavani, +6 authors A. Alizadeh : A new experimentally validated formula to calculate the QT-interval in the presence of left bundle branch block holds true in the clinical setting. Tex Heart Inst J. Cardiology 130(4):207210, Frommeyer G, Bogossian H, Pechlivanidou E, Conzen P, Gemein C et al (2017) Applicability of a novel formula (Bogossian formula) for evaluation of the QT-interval in heart failure and left bundle branch block due to right ventricular pacing. In the non-apical group these values were 430 34 ms in paced and 416 32 ms in intrinsic rhythm. doi: 10.1111/ijcp.13250. 2016 in press, Markewitz A (2015) Annual report 2013 of the German Cardiac Pacemaker And Defibrillator RegisterPart 2: implantable cardioverter-defibrillators. 2020 Sep;43(9):957-962. doi: 10.1002/clc.23389. METHODS: A total of 163 patients with a cardiac one- or two-chamber pacemaker were included in this prospective, multicentre observational study. JT interval; Left bundle branch block; Long QT; Pacemaker; QT formula; QT interval. Unfortunately the Bazett correction overcorrects with heart rates >110 bpm and undercorrects with heart rates < 60 bpm. -, Herzschrittmacherther Elektrophysiol. and covers all kinds of ventricular conduction defects (LBBB, RBBB and intraventricular delay) and the complete heart-rate spectrum (Table 1 ). 2018 Nov;72(11):e13250. The QTc interval was overestimated by QTc of 25 21 ms (mean deviation 5.7%) when using the Bogossian formula. Here we demonstrate the applicability of the "Bogossian formula" in pacemaker patients with LBBB due to apical or nonapical right ventricular (RV) pacing and preserved left ventricular function. This tool is a statistical model and is not a substitute for an individual treatment plan developed by a health care provider with personal knowledge of a specific patient. Please enable it to take advantage of the complete set of features! The https:// ensures that you are connecting to the AU - Schmitt,J, This site needs JavaScript to work properly. Division of Electrophysiology, Department of Cardiovascular Medicine, University of Mnster, Mnster, Germany. Eighty-three patients (78 9 years; male n = 83) with apical and eighty patients (71 13 years; male n = 80) with non-apical RV pacing were included in this study. In the apical group the QTmc was determined to be 44439ms in paced rhythm and the QTc interval 41336ms in intrinsic rhythm. EKG fr Laien und fr NotfallmedizinerInnen. Assessment of QTc and Risk of Torsades de Pointes in Ventricular Conduction Delay and Pacing: A Review of the Literature and Call to Action. This site needs JavaScript to work properly. National Library of Medicine Inclusion criteria were: no permanent right ventricular stimulation, an intrinsic QRS interval of <120 ms, and reduced left ventricular function. 2020 Sep;43(9):957-962. doi: 10.1002/clc.23389. Results: What is the golden rule for solving equations? Am J Cardiol 55(11):13321338 CrossRef, Zurck zum Zitat Bogossian H, Frommeyer G, Ninios I, Hasan F, Nguyen QS et al (2014) New formula for evaluation of the QT interval in patients with left bundle branch block. Conclusion In combination with the Hodge formula, the Boggosian formula delivered the best results in comparing the true QTc interval in narrow QRS with the QTmc interval in the presence of a bifascicular block. PMC @article{Bogossian2017ANE, title={A new experimentally validated formula to calculate the QT interval in the presence of left bundle branch block holds true in the clinical setting}, author={Harilaos Bogossian and Gerrit Frommeyer and Ilias Ninios and Eleni Pechlivanidou and Fuad Hasan and Quy Suu Nguyen and Dejan Miji{\'c} and Axel Kloppe and . Clipboard, Search History, and several other advanced features are temporarily unavailable. Before Bethesda, MD 20894, Web Policies Applicability of a Novel Formula (Bogossian formula) for Evaluation of the QT-Interval in Heart Failure and Left Bundle Branch Block Due to Right Ventricular Pacing. Bookshelf 2017 Jul;22(4):e12458. HHS Vulnerability Disclosure, Help Unfortunately the Bazett correction overcorrects with heart rates >110 bpm and undercorrects with heart rates < 60 bpm. The corrected QTc interval was compared in each patient with the QTc interval during intrinsic rhythm. Keywords: Department of Cardiology and Angiology, Medical Clinic I, University Clinic of Gieen, Gieen, Germany. 2020 Sep 19;30:100636. doi: 10.1016/j.ijcha.2020.100636. However, the investigators cautioned that a 25 ms overestimation of the QT interval should be expected with this formula [ 9 ]. Long-term outcomes of His bundle pacing in patients with heart failure with left bundle branch block. Sagie A, Larson MG, Goldberg RJ, Bengston JR, Levy D. Luo S, Michler K, Johnton P, Macfarlane PW. New formula for defining "normal" and "prolonged" QT in patients with bundle branch block. Kommentar * document.getElementById("comment").setAttribute( "id", "a3a02925a44b9a4347b4dd67a49eb968" );document.getElementById("cdef1402a5").setAttribute( "id", "comment" ); Meinen Namen, meine E-Mail-Adresse und meine Website in diesem Browser, fr die nchste Kommentierung, speichern. There is yet more to learn about repolarization. Here we demonstrate the applicability of the "Bogossian formula" in pacemaker patients with LBBB due to apical or nonapical right ventricular (RV) pacing and preserved left ventricular function. 2015 Dec;26(4):374-98 Unauthorized use of these marks is strictly prohibited. Cardiology 130(4):207210 CrossRef, Zurck zum Zitat Frommeyer G, Bogossian H, Pechlivanidou E, Conzen P, Gemein C et al (2017) Applicability of a novel formula (Bogossian formula) for evaluation of the QT-interval in heart failure and left bundle branch block due to right ventricular pacing. Subsequently, rate-correction formula should be applied as usual. Google Scholar, Bogossian H, Frommeyer G, Ninios I, Hasan F, Nguyen QS et al (2014) New formula for evaluation of the QT interval in patients with left bundle branch block. Accessibility Bogossian et al, Heart Rhythm 2015. . Wang B, Zhang LI, Cong P, Chu H, Liu Y, Liu J, Surkis W, Xia Y. J Cardiovasc Electrophysiol. Epub 2018 Jan 31. KW - QT interval ER -. 2020 Sep 19;30:100636. doi: 10.1016/j.ijcha.2020.100636. In 2014, a new formula for the evaluation of. In the non-apical group these values were 430 34 ms in paced and 416 32 ms in intrinsic rhythm. American Journal of Cardiology 1992 September 15, 70 (7): 797-801, Journal of Electrocardiology 2004, 37 Suppl: 81-90. eCollection 2020 Oct. Ann Noninvasive Electrocardiol. Unfortunately the Bazett correction overcorrects with heart rates >110 bpm and undercorrects with heart rates < 60 bpm. Y1 - 2018/05/11/ 2017 Jul;22(4):e12475. The issue that QT duration is not exclusively depending on the prolonged depolarization time during LBBB, but that there are many features including heart rate, electrophysiological remodeling and clinical condition of the patient that may contribute is raised, however, in some population the authors' formula works fairly well in others it tends to overestimate the QTtime.