Background: Handheld electrocardiograms (ECGs) can be used easily in remote centers at low cost and are therefore attractive options for rural, low-income settings. A modification to the Kardia 6L ECG has been developed to record chest leads V2 and V4 by placing the device electrodes in standard V2 and V4 position.
Objective: The study sought to validate this novel technique against the 12-lead ECG in a multicenter cohort from Africa and the United Kingdom to determine whether recordings are adequate for clinical use.
Methods: Adults >18 years of age who required an ECG as part of routine care were invited to participate. A 12-lead ECG was obtained followed by a 6-lead ECG using the Kardia 6L, then V2 and V4 chest lead equivalents were recorded. The primary endpoint was agreement between QT interval measurement in V2 and V4 on 12-lead ECG and Kardia 6L. Secondary endpoints assessed included rate, rhythm, PR interval, QRS duration, QRS amplitude, and ST-segment abnormalities.
Results: A total of 1786 recordings were collected from 11 sites. Hypertension was the primary indication for ECG (28%). The coefficient of determination for QT interval in leads V2 and V4 was 0.59 and 0.61, respectively, within the prespecified limit of agreement. The adjusted R2 for multiple ECG parameters was >0.5, indicating satisfactory agreement.
Conclusion: Modified chest lead recordings using the Kardia 6L handheld ECG recorder compared well with gold standard 12-lead ECG recordings and provide a basis for future simulated 12-lead ECG recordings using the Kardia 6L. This could improve accessibility of high-quality ECG recording and interpretation in rural, low-income settings.
Keywords: 6-lead ECG; Chest leads; ECG; Electrocardiogram; Handheld ECG.
© 2025 Heart Rhythm Society. Published by Elsevier Inc.