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Accepted for/Published in: JMIR Cardio

Date Submitted: Oct 27, 2025
Open Peer Review Period: Nov 6, 2025 - Jan 1, 2026
Date Accepted: Sep 9, 2026
(closed for review but you can still tweet)

The final, peer-reviewed published version of this preprint can be found here:

Generation of 12-Lead Electrocardiogram Using Smartwatches in Patients With Cardiac Conditions: Clinical Validation Study

Buelga Suárez M, Plaza Seco C, Matía Francés R, Alonso Salinas GL, Blanco Velasco M

Generation of 12-Lead Electrocardiogram Using Smartwatches in Patients With Cardiac Conditions: Clinical Validation Study

JMIR Cardio 2026;10:e86621

DOI: 10.2196/86621

PMID: 42987258

Generation of 12-Lead ECG Using Smartwatches in Patients with Cardiac Conditions: A Clinical Validation Study

  • Mauro Buelga Suárez; 
  • Carmen Plaza Seco; 
  • Roberto Matía Francés; 
  • Gonzalo Luis Alonso Salinas; 
  • Manuel Blanco Velasco

ABSTRACT

Background:

While smartwatches have revolutionized personal health monitoring, their utility for comprehensive cardiac assessment remains limited by single-lead electrocardiogram (ECG) acquisition. This study introduces a novel software-based methodology to reconstruct a full 12-lead ECG from sequential smartwatch recordings, aiming for diagnostic comparability with conventional systems.

Objective:

We present a proof-of-concept clinical validation of this approach, addressing a critical unmet need in accessible cardiac diagnostics.

Methods:

A signal processing pipeline was developed to preserve ECG morphology across sequential smartwatch lead recordings, achieving synchronization via RR interval–based temporal resampling to generate a coherent 12-lead ECG. A clinical validation study was conducted in 20 patients with diverse cardiac pathologies and 2 healthy controls. Smartwatch-derived ECGs were compared with standard recordings. Diagnostic accuracy and visual interpretability were assessed by 85 healthcare professionals through a structured questionnaire. An independent arrhythmologist provided qualitative clinical validation for all cases.

Results:

The primary objective of reconstructing a 12-lead ECG from smartwatch signals was successfully achieved. Visual correlation scores between smartwatch-derived and conventional ECGs ranged from 77% to 91.4%, with a mean of 81%, indicating strong concordance. An average of 95.5% alignment in the electrical axis was observed. The highest diagnostic agreement was found in ischemic heart disease and bundle branch blocks, supporting clinical relevance.

Conclusions:

This study demonstrates proof-of-concept for reconstructing a 12-lead ECG from smartwatch-acquired signals with diagnostic comparability to conventional systems. This method expands smartwatch ECG capabilities, enabling accessible, advanced cardiovascular diagnostics and proactive patient monitoring. A European patent has been filed for this technology (reference:EP25382712.5).


 Citation

Please cite as:

Buelga Suárez M, Plaza Seco C, Matía Francés R, Alonso Salinas GL, Blanco Velasco M

Generation of 12-Lead Electrocardiogram Using Smartwatches in Patients With Cardiac Conditions: Clinical Validation Study

JMIR Cardio 2026;10:e86621

DOI: 10.2196/86621

PMID: 42987258

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