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Published on: December 11, 2019
Validation of smartwatch electrocardiogram intervals in children compared to standard 12 lead electrocardiograms
Julia Ernstsson1, Birgitta Svensson1,2, Petru Liuba1,2
1Department of Clinical Sciences Lund, Lund University, Lund, Sweden.
Insights
Smartwatch electrocardiograms (ECG) show good accuracy for heart rate and intervals in children, but QTc measurements improve with manual input. This technology aids remote monitoring for pediatric cardiac conditions.
Area of Science:
- Pediatric Cardiology
- Digital Health Technology
- Electrocardiography
Background:
- Smartwatches offer accessible one-lead electrocardiograms (ECG) for arrhythmia detection.
- Previous studies validated smartwatch ECG accuracy in adults, but not in children.
- Home-based smartwatch ECG monitoring could enhance pediatric cardiac care, especially for QTc-prolonging medications.
Purpose of the Study:
- To validate smartwatch-measured ECG intervals against standard 12-lead ECGs in children and adolescents.
- To assess the accuracy of both automated and manual smartwatch ECG measurements.
Main Methods:
- Prospective study involving 100 children and adolescents (ages 5-17) at a national pediatric heart center.
- Simultaneous smartwatch (Withings ScanWatch) and 12-lead ECG recordings were obtained.
- ECG intervals were analyzed using automated and manual measurements, with intraclass correlation coefficients and Bland-Altman plots.
Main Results:
- Automated smartwatch ECGs demonstrated excellent agreement for heart rate (ICC 0.97) and good agreement for PR (0.86) and QT (0.8) intervals.
- Moderate agreement was found for automated QRS duration (0.7) and QTc intervals (0.53).
- Manual smartwatch measurements significantly improved validity, particularly for PR (0.93), QRS (0.92), QT (0.95), and QTc (0.84) intervals.
Conclusions:
- Automated smartwatch ECGs are most reliable for heart rate measurement in children.
- Automated smartwatch QTc interval accuracy is limited but can be improved through manual measurements.
- Smartwatch ECGs hold potential for pediatric remote monitoring, with manual analysis enhancing reliability.
Abstract:
Lay people are now able to obtain one-lead electrocardiograms (ECG) using smartwatches, which facilitates documentation of arrhythmias. The accuracy of smartwatch derived ECG intervals has not been validated in children though. Home-based monitoring of ECG intervals using a smartwatch could improve monitoring of children, e.g. when taking QTc prolonging medications. The aim of this study was to validate the ECG intervals measured by smartwatch in comparison to standard 12-lead ECGs in children and adolescents. Prospective study of children (age 5-17 years) at the outpatient clinic of a national pediatric heart center. Patients underwent a smartwatch ECG (ScanWatch, Withings) and a simultaneous standard 12-lead ECG. ECG intervals were measured both automatically and manually from the smartwatch ECG and the 12-lead ECG. Intraclass correlation coefficients and Bland-Altman plots were performed. 100 patients (54% male, median age 12.9 (IQR 8.7-15.6) were enrolled. The ICC calculated from the automated smartwatch and automated 12-lead ECG were excellent for heart rate (ICC 0.97, p < 0.001), good for the PR and QT intervals (ICC 0.86 and 0.8, p < 0.001), and moderate for the QRS duration and QTc interval (ICC 0.7 and 0.53, p < 0.001). When using manual measurements for the smartwatch ECG, validity was improved for the PR interval (ICC 0.93, p < 0.001), QRS duration (ICC 0.92, p < 0.001), QT (ICC 0.95, p < 0.001) and QTc interval (ICC 0.84, p < 0.001).
Conclusion:
Automated smartwatch intervals are most reliable measuring the heart rate. The automated smartwatch QTc intervals are less reliable, but this may be improved by manual measurements.
What Is Known:
In adults, smartwatch derived ECG intervals measured manually have previously been shown to be accurate, though agreement for automated QTc may be fair.
What Is New:
In children, automated smartwatch QTc intervals are less reliable than RR, PR, QRS and uncorrected QT interval. Accuracy of the QTc can be improved by peroforming manual measurements.
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