Beyond the wrist: Using a smartwatch electrocardiogram to detect electrocardiographic abnormalities

Area of Science:

• Cardiology
• Biomedical Engineering
• Medical Devices

Background:

• Smartwatch electrocardiograms (ECG) worn on the wrist offer valuable but limited diagnostic information.
• Existing smartwatch ECG technology requires enhancement for comprehensive cardiac assessment.

Purpose of the Study:

• To assess the diagnostic benefits of smartwatch ECGs placed on the ankle and chest compared to traditional 12-lead ECGs.
• To evaluate the improvement in detecting various electrocardiographic abnormalities with extended smartwatch lead placement.

Main Methods:

• Conducted 12-lead ECG and smartwatch ECG recordings (wrist-lead I - AW-I; wrist, ankle, and chest leads - AW-4) in 260 patients.
• Compared diagnoses from AW-I and AW-4 (three-cardiologist consensus) against 12-lead ECG diagnoses to determine sensitivity and specificity.

Main Results:

• AW-I demonstrated high accuracy for atrial fibrillation (96% sensitivity) and bundle branch block (85% sensitivity).
• AW-4 significantly improved the detection of abnormal ECGs (91% vs. 80% sensitivity) and specific abnormalities like T-wave changes and pathological Q-waves.
• AW-4 enhanced differentiation between bradyarrhythmias and tachyarrhythmias, including distinguishing atrial fibrillation from atrial flutter/tachycardia.

Conclusions:

• Wrist-worn smartwatch ECGs are effective for diagnosing atrial fibrillation and bundle branch block.
• Utilizing additional smartwatch leads (AW-4) substantially increases accuracy for detecting ECG abnormalities and repolarization changes.
• Extended smartwatch lead placement improves the classification of various brady- and tachyarrhythmias.