The development and validation of an easy to use automatic QT-interval algorithm.

Autor: Ben J M Hermans, Arja S Vink, Frank C Bennis, Luc H Filippini, Veronique M F Meijborg, Arthur A M Wilde, Laurent Pison, Pieter G Postema, Tammo Delhaas
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: PLoS ONE, Vol 12, Iss 9, p e0184352 (2017)
Druh dokumentu: article
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0184352
Popis: To evaluate QT-interval dynamics in patients and in drug safety analysis, beat-to-beat QT-interval measurements are increasingly used. However, interobserver differences, aberrant T-wave morphologies and changes in heart axis might hamper accurate QT-interval measurements.To develop and validate a QT-interval algorithm robust to heart axis orientation and T-wave morphology that can be applied on a beat-to-beat basis.Additionally to standard ECG leads, the root mean square (ECGRMS), standard deviation and vectorcardiogram were used. QRS-onset was defined from the ECGRMS. T-wave end was defined per individual lead and scalar ECG using an automated tangent method. A median of all T-wave ends was used as the general T-wave end per beat. Supine-standing tests of 73 patients with Long-QT syndrome (LQTS) and 54 controls were used because they have wide ranges of RR and QT-intervals as well as changes in T-wave morphology and heart axis orientation. For each subject, automatically estimated QT-intervals in three random complexes chosen from the low, middle and high RR range, were compared with manually measured QT-intervals by three observers.After visual inspection of the randomly selected complexes, 21 complexes were excluded because of evident noise, too flat T-waves or premature ventricular beats. Bland-Altman analyses of automatically and manually determined QT-intervals showed a bias of 0.9) between the algorithm and all observers individually as well as between the algorithm and the mean QT-interval of the observers.Our automated algorithm provides reliable beat-to-beat QT-interval assessment, robust to heart axis and T-wave morphology.
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