Real-time multichannel system for beat-to-beat QT interval variability

Institute of Physiology, School of Medicine, University of Ljubljana, Ljubljana 1104, Slovenia.
Journal of electrocardiology (Impact Factor: 1.36). 11/2006; 39(4):358-67. DOI: 10.1016/j.jelectrocard.2006.03.004
Source: PubMed


The measurement of beat-to-beat QT interval variability (QTV) shows clinical promise for identifying several types of cardiac pathology. However, until now, there has been no device capable of displaying, in real time on a beat-to-beat basis, changes in QTV in all 12 conventional leads in a continuously monitored patient. Although several software programs have been designed to analyze QTV, heretofore, such programs have all involved only a few channels (at most) and/or have required laborious user interaction or offline calculations and postprocessing, limiting their clinical utility. This article describes a PC-based electrocardiogram software program recently codeveloped by our laboratories that, in real time, acquires, analyzes, and displays QTV in each of the 8 independent channels that constitute the 12-lead conventional electrocardiogram. The system also analyzes and displays the QTV from QT-interval signals that are derived from multiple channels and from singular value decomposition such that the effect of noise and other artifacts on the QTV results are substantially reduced compared with existing single-channel methods.

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Available from: Todd T Schlegel, Mar 31, 2015
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    • "Baumert et al. [36] compared three algorithms, template stretch [24], template shift [37] and a conventional (derivative) approach [35], and showed that using these data the template based algorithms outperform the other method in most cases. However, the authors emphasize certain limitations of the comparison , arising e.g. from differing beat rejection strategies. "
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