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Nevertheless, compared to adults, children have higher heart rates (especially during postural provocations) and Bazett correction is also known to lead to artificially prolonged QTc values at increased heart rates. This study assessed the incidence of erroneously increased QTc values in normal children without QT abnormalities.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Continuous 12-lead ECGs were recorded in 332 healthy children (166 girls) aged 10.7\u2009\u00b1\u20092.6\u2009years while they performed postural manoeuvring consisting of episodes (in the following order) of supine, sitting, standing, supine, standing, sitting, and supine positions, each lasting 10\u2009min. Detailed analyses of QT\/RR profiles confirmed the absence of prolonged individually corrected QTc interval in each child. Heart rate and QT intervals were measured in 10-s ECG segments and in each segment, QTc intervals were obtained using Bazett, Fridericia, and Framingham formulas. In each child, the heart rates and QTc values obtained during supine, sitting and standing positions were averaged. QTc durations by the three formulas were classified to &lt;\u2009440\u2009ms, 440\u2013460\u2009ms, 460\u2013480\u2009ms, and\u2009&gt;\u2009480\u2009ms.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>At supine position, averaged heart rate was 77.5\u2009\u00b1\u200910.5 beat per minute (bpm) and Bazett, Fridericia and Framingham QTc intervals were 425.3\u2009\u00b1\u200915.8, 407.8\u2009\u00b1\u200913.9, and 408.2\u2009\u00b1\u200913.1\u2009ms, respectively. At sitting and standing, averaged heart rate increased to 90.9\u2009\u00b1\u200910.1 and 100.9\u2009\u00b1\u200910.5\u2009bpm, respectively. While Fridericia and Framingham formulas showed only minimal QTc changes, Bazett correction led to QTc increases to 435\u2009\u00b1\u200915.1 and 444.9\u2009\u00b1\u200915.9\u2009ms at sitting and standing, respectively. At sitting, Bazett correction identified 51, 4, and 0 children as having the QTc intervals 440\u2013460, 460\u2013480, and\u2009&gt;\u2009480\u2009ms, respectively. At sitting, these numbers increased to 118, 11, and 1, while on standing these numbers were 151, 45, and 5, respectively. Irrespective of the postural position, Fridericia and Framingham formulas identified only a small number (&lt;\u20097) of children with QT interval between 440 and 460\u2009ms and no children with longer QTc.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>During screening for LQTS in children, the use of Bazett formula leads to a high number of false positive cases especially if the heart rates are increased (e.g. by postural manoeuvring). The use of Fridericia formula can be recommended to replace the Bazett correction not only for adult but also for paediatric ECGs.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1186\/s12887-020-02460-8","type":"journal-article","created":{"date-parts":[[2020,12,14]],"date-time":"2020-12-14T03:02:54Z","timestamp":1607914974000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":32,"title":["Problems with Bazett QTc correction in paediatric screening of prolonged QTc interval"],"prefix":"10.1186","volume":"20","author":[{"given":"Irena","family":"Andr\u0161ov\u00e1","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Katerina","family":"Hnatkova","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kate\u0159ina","family":"Hel\u00e1nov\u00e1","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Martina","family":"\u0160i\u0161\u00e1kov\u00e1","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tom\u00e1\u0161","family":"Novotn\u00fd","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Petr","family":"Kala","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3792-1407","authenticated-orcid":false,"given":"Marek","family":"Malik","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2020,12,14]]},"reference":[{"key":"2460_CR1","first-page":"351","volume":"18","author":"AH Garrod","year":"1870","unstructured":"Garrod AH. 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The parents or legal guardians of all participants gave informed written consent according to the Helsinki declaration.","order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"The Informed consent provided by the parents or legal guardians of all participants included the agreement of scientific use of the data obtained. No data are presented that would allow individual study participants to be identified.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare that they have no competing interests.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"558"}}