Abstract
Drug-induced long QT syndrome (diLQTS), characterized by a prolongation of the QT-interval on the electrocardiogram (ECG), is a serious adverse drug reaction that can cause the life-threatening arrhythmia Torsade de Points (TdP). Self-monitoring for diLQTS could therefore save lives, but detecting it on the ECG is difficult, particularly at high and low heart rates. In this paper, we evaluate whether using a pseudo-colouring visualisation technique and changing the coordinate system (Cartesian vs. Polar) can support lay people in identifying QT-prolongation at varying heart rates. Four visualisation techniques were evaluated using a counterbalanced repeated measures design including Cartesian no-colouring, Cartesian pseudo-colouring, Polar no-colouring and Polar pseudo-colouring. We used a multi-reader, multi-case (MRMC) receiver operating characteristic (ROC) study design within a psychophysical paradigm, along with eye-tracking technology. Forty-three lay participants read forty ECGs (TdP risk n = 20, no risk n = 20), classifying each QT-interval as normal/abnormal, and rating their confidence on a 6-point scale. The results show that introducing pseudo-colouring to the ECG significantly increased accurate detection of QT-interval prolongation regardless of heart rate, T-wave morphology and coordinate system. Pseudo-colour also helped to reduce reaction times and increased satisfaction when reading the ECGs. Eye movement analysis indicated that pseudo-colour helped to focus visual attention on the areas of the ECG crucial to detecting QT-prolongation. The study indicates that pseudo-colouring enables lay people to visually identify drug-induced QT-prolongation regardless of heart rate, with implications for the more rapid identification and management of diLQTS.
Highlights
Background and significanceAn electrocardiogram (ECG or EKG) is a graphical representation of the electrical activity of the heart, widely used as a clinical tool for monitoring heart function and detecting cardiac
The DBM MRMC method uses jackknifing and analysis of variance (ANOVA) methods and we considered both readers and cases as random variables; this allows the results to be generalised to the population of readers and cases
All anonymised data and related metadata underpinning the findings reported in this article can be found in [62]
Summary
An electrocardiogram (ECG or EKG) is a graphical representation of the electrical activity of the heart, widely used as a clinical tool for monitoring heart function and detecting cardiac. In an earlier feasibility study, we found that superimposing pseudo-colouring on the ECG using a spectrum-approximation colour sequence significantly improved people’s ability to detect increases in the QT-interval at a low normal heart rate, when compared with a reference ECG stimulus showing a normal QT baseline [51]. This initial investigation had several limitations that affected the generalisability of the results. This study tests the technique by presenting the ECGs one by one, asking participants to judge whether QT-prolongation has occurred when viewing just a single image, rather than comparing it with a baseline
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.