Underestimated and unreported prolonged QTc by automated ECG analysis in patients on methadone: can we rely on computer reading?

Talebi, Soheila; Azhir, Alaleh; Zuber, Samuel M.; Soman, Sandeep; Visco, Ferdinand; Totouom-Tangho, Holly; Kalantar, Hadi; Hassen, Getaw Worku

doi:10.1080/ac.70.2.3073513

Cited by 13 publications

(12 citation statements)

References 14 publications

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“…Automated QTc measurement is usually not recommended because it can underestimate QTc 21. Only recently continuous QTc measurement was validated in critically ill patients, but only in patients with QRS <120 ms 22.…”

Section: Discussionmentioning

confidence: 99%

QTc prolongation during erythromycin used as prokinetic agent in ICU patients

et al. 2017

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BackgroundHigh-dose erythromycin used as antibiotic prolongs QTc interval. Low-dose erythromycin is frequently used as a prokinetic agent, especially in patients in the intensive care unit (ICU). It is unknown whether low-dose erythromycin affects cardiac repolarisation and puts patients at risk for torsades de pointes.MethodsIn this prospective study, we included ICU patients treated with erythromycin as prokinetic in a dose of 200 mg twice a day. An ECG was performed before, 15 min and 24 hours after the start of erythromycin. Cardiac repolarisation was assessed by rate-corrected analysis of the QT interval (QTc) on the ECG by two independent investigators. Starting or stopping other possibly QTc prolonging drugs during the study period was an exclusion criterion. Wilcoxon signed-rank test and Friedman's test were used for statistical analysis to assess prolongation of QTc. Primary outcome was defined by the prolongation of QTc after 15 min and 24 hours.Results51 patients were eligible for this study. In these patients, QTc increased significantly from 430 ms at baseline to 439 ms (p=0.03) after 15 min and 444 ms (p=0.01) after 24 hours. After 15 min and 24 hours, the upper limit of 95% CI for prolongation of QTc was well above 10 ms. No QTc-related arrhythmias were seen.ConclusionsDuring treatment with erythromycin in a dose of 200 mg twice a day. QTc prolonged mildly but significantly. Sequential ECG registration should be performed when low-dose erythromycin is prescribed, especially in the presence of other risk factor for QTc prolongation.

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Section: Discussionmentioning

confidence: 99%

QTc prolongation during erythromycin used as prokinetic agent in ICU patients

et al. 2017

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“…Automated QT measurement algorithms have proved unsatisfactory for detecting LQTS in particular [33][34][35][36][37][38][39]. Garg and Lehmann [33] found that even a widely used computerized ECG analysis system was not able to detect QT-interval prolongation in 52.5% of patients affected.…”

Section: Plos Onementioning

confidence: 99%

“…Garg and Lehmann [33] found that even a widely used computerized ECG analysis system was not able to detect QT-interval prolongation in 52.5% of patients affected. Research has also shown that drug-induced QT-prolongation can be underestimated and under-reported by computerised methods in patients on Methadone, a drug that is infamous for prolonging the QT-interval and increasing the risk of TdP [38]. A major challenge for automated QT algorithms is identifying the precise end of the T-wave (the terminal point), especially when the T-wave's morphology is abnormal [2,40,41].…”

Section: Plos Onementioning

confidence: 99%

“…These indicators are lost by automated QT algorithms, however, as they work by abstracting the ECG data into a number (the calculated length of the QT-interval). As such, the human visual validation of QT-prolongation on the ECG remains mandatory in clinical practice, and provides the richest information for recognizing LQTS [30,[33][34][35][36][37][38][39].…”

Section: Plos Onementioning

confidence: 99%

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Pseudo-colouring an ECG enables lay people to detect QT-interval prolongation regardless of heart rate

et al. 2020

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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 multireader, 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. Pseudocolour 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.

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“…Large studies have shown the sensitivity of automated ECG algorithms to be below 50% for detecting prolonged QT intervals. 4,5 Studies comparing manual 49 the available evidence supports it being in the conditional risk category 50 with computerised calculation have returned findings favouring manual assessment by trained observers; 6 however, in a large study of 902 physicians, less than 50% of cardiologists and less than 40% of other physicians were able to correctly identify a prolonged QT interval. 7 Thus, it is imperative that clinicians are able to measure the QT interval correctly, given the inaccuracies of automated measurement.…”

Section: Inaccuracies Of Qt Measurementmentioning

confidence: 99%