Dataset Information

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

ABSTRACT:

Background

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.

Objective

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.

Methods

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.

Results

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 <4ms and limits of agreement of ±25ms. Intra-class coefficient indicated excellent agreement (>0.9) between the algorithm and all observers individually as well as between the algorithm and the mean QT-interval of the observers.

Conclusion

Our automated algorithm provides reliable beat-to-beat QT-interval assessment, robust to heart axis and T-wave morphology.

SUBMITTER: Hermans BJM

PROVIDER: S-EPMC5581168 | biostudies-literature | 2017

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

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

Hermans Ben J M BJM Vink Arja S AS Bennis Frank C FC Filippini Luc H LH Meijborg Veronique M F VMF Wilde Arthur A M AAM Pison Laurent L Postema Pieter G PG Delhaas Tammo T

PloS one 20170901 9

<h4>Background</h4>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.<h4>Objective</h4>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.<h4>Methods</h4>Additionally to standard EC ...[more]

PMID: 28863167

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Dataset Information

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

Background

Objective

Methods

Results

Conclusion

Publications

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

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