Smartwatch-Based Heart Rate Detection in Atrial, Ventricular and Pulseless Arrhythmias

Area of Science:

• Cardiology
• Biomedical Engineering
• Wearable Technology

Background:

• Smartwatches offer non-invasive heart rate (HR) monitoring for atrial fibrillation screening.
• Accuracy of HR detection during other arrhythmias needs further study.

Purpose of the Study:

• Assess HR measurement accuracy of Apple Watch (AW) and Fitbit (FB) during induced and paced arrhythmias.
• Evaluate device performance at onset, during, and termination of arrhythmias.

Main Methods:

• Intraprocedural fitting of AW and FB on patients undergoing electrophysiology studies.
• Recording HRs during various paced/induced arrhythmias; confirmed with intracardiac electrograms and 12-lead ECG.
• Assessed accuracy as HR within ±10% of the true rate.

Main Results:

• Analyzed 322 cardiac rhythms from 32 patients.
• AW and FB showed reasonable HR detection during sinus rhythm (100% vs 87%) and supraventricular tachycardia (SVT) (89% vs 86%).
• Both devices performed poorly during SVT termination (62% vs 41%) and ventricular tachycardia (41% vs 16%); failed to detect HR changes in ventricular fibrillation or asystole.

Conclusions:

• Apple Watch and Fitbit offer reasonable HR accuracy for regular supraventricular rhythms.
• Devices struggle with arrhythmia terminations and ventricular arrhythmias.
• Caution is advised when using HR trends from wearables to assess cardiac arrhythmias.