Feasibility and Reliability of SmartWatch to Obtain 3-Lead Electrocardiogram Recordings

Abstract

Some of the recently released smartwatch products feature a single-lead electrocardiogram (ECG) recording capability. The reliability of obtaining 3-lead ECG with smartwatches is yet to be confirmed in a large study. This study aimed to assess the feasibility and reliability of smartwatch to obtain 3-lead ECG recordings, the classical Einthoven ECG leads I-III compared to standard ECG. To record lead I, the watch was worn on the left wrist and the right index finger was placed on the digital crown for 30 s. For lead II, the watch was placed on the lower abdomen and the right index finger was placed on the digital crown for 30 s. For lead III, the same process was repeated with the left index finger. Spearman correlation and Bland-Altman tests were used for data analysis. A total of 300 smartwatch ECG tracings were successfully obtained. ECG waves’ characteristics of all three leads obtained from the smartwatch had a similar duration, amplitude, and polarity compared to standard ECG. The results of this study suggested that the examined smartwatch (Apple Watch Series 4) could obtain 3-lead ECG tracings, including Einthoven leads I, II, and III by placing the smartwatch on the described positions.

World Heart Federation Roadmap on Atrial Fibrillation – A 2020 Update

“…Proprietary technologies already allow direct recording and interpretation of an ECG tracing from a smartwatch [ 93 ]. For example, the Kardia Band used an Apple smartwatch to detect possible AF from intermittent PPG registrations, with user wrist haptic/buzz notification to record an ECG from the band, followed by an automated ECG interpretation [ 94 ], but this device is no longer available.…”

Feasibility and Reliability of Smartwatch to Obtain Precordial Lead Electrocardiogram Recordings

“…In the current study, we included only adult participants with sinus rhythm to validate SW-ECG precordial leads. However, in the other studies the focus was either on pediatric patients, or on the accuracy of SWs to capture cardiac arrhythmias such as atrial fibrillation in adults, the feasibility of obtaining the Einthoven leads I-III, and the ability of handheld devices to detect ST-segment changes [ 6 , 7 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ].…”

“…A study investigating the performance of handheld ECG devices to detect atrial fibrillation in a geriatric ward and a cardiology ward found that in 21.4% of the elderly patients in the geriatric ward, a recording with a handheld device could not be performed, while in the cardiology ward with younger patients, it was only 7% [ 21 ]. In another study by our research group, we found that patients had no problems with recording Einthoven leads I-III with a SW by themselves after a short training [ 10 ]. We assumed that it is more difficult for patients to record the precordial leads by themselves and position the SW at the right location than to record lead I-III, which only needs positioning of the SW on the wrist and the lower abdomen.…”

“…During recent years, different research groups have tried to assess the feasibility and reliability of SWs to obtain ECG recordings. However, these attempts were mostly limited to studies that assessed qualitatively and quantitatively the similarity between the ECG recordings of the SWs and standard ECGs in the classical Einthoven ECG leads I-III or focused on the accuracy of the SW-ECG in pediatric patients with and without congenital heart disease [ 10 , 11 , 12 ]. A standard 12-lead ECG gives more information than lead I-III by recording the precordial leads V1–V6, and the Goldberger leads (aVR, aVL, and aVF) [ 13 ].…”

Use of the Apple Watch iECG in adult congenital heart disease patients

“…1 The positioning of the Apple Watch Series 4 for obtaining leads I, II, and III using the Einthoven triangle. In the Apple Watch, the negative electrode is placed in the digital crown and the positive electrode is on the back crystal of the watch [ 15 ]. …”