COMPARISON OF APPLE WATCH SERIES 4 VS. KARDIAMOBILE: A TALE OF TWO DEVICES

Abstract

BACKGROUND Cardiac arrhythmias such as sinus rhythm (SR) and atrial fibrillation (AF) are most often diagnosed using the gold-standard 12-lead ECG, however it can only be used in clinics and hospitals. This is where newer technologies such as digital health devices excel, since they are ultra-portable devices that are user-operated and offer the ability to record ECGs regardless of location. Apple Watch Series 4 (AW4) and KardiaMobile 2-lead model (KM) are two of the most popular devices that are officially approved by the FDA. However, there is still a lack of knowledge regarding the AW4’s and KM's ability and accuracy to detect both sinus (SR) and atrial fibrillation (AF) rhythms in clinical situations. This paper aims to determine the practicality of using digital health devices, such as the AW4 and KM, in modern medical practice by assessing and comparing their accuracies in identifying heart rhythms and heart rate. METHODS AND RESULTS A total of 200 patients, all of whom were scheduled for a visit to the at Toronto Heart Centre clinic were enrolled from Jan 2018 to Dec 2019. A 12-lead electrocardiogram (ECG) was obtained, followed by AW4 (WatchOS 5.3) and KM, within 5 minutes of one another. Each session with every patient consisted of an ECG recording from a 12-lead ECG, from KM's ECG function, from AW4’s ECG function (AECG), and a heart rate recording from AW4’s photoplethysmography function (APPG). Of the total 200 patients, the mean age was 63 years ± 15 and they were predominantly male at 59%. There were 162 (81%) patients who were in sinus rhythm and 38 (19%) who were in atrial fibrillation. Rhythm detection accuracies for sinus rhythm were: 100% for AW4 and 99.03% for KM, meanwhile those for Afib were: 90.48% for AW4 and 100% for KM. Heart rate accuracies for sinus rhythm were: 94.39% for KM, 90.65% for Apple PPG (APPG), and 96.26% for Apple ECG (AECG). Heart rate accuracies for Afib were: 91.30% for KM, 82.61% for AP, and 86.96% for AE. CONCLUSION The results demonstrate that both AW4 and KM are highly capable in detecting rhythm and HR. There is a non-significant trend in favour of KM in rhythm detection and accuracy, compared with AW4. The difference is mainly due to artefacts (e.g. tremors) and strap size fitting for AW4. Cardiac arrhythmias such as sinus rhythm (SR) and atrial fibrillation (AF) are most often diagnosed using the gold-standard 12-lead ECG, however it can only be used in clinics and hospitals. This is where newer technologies such as digital health devices excel, since they are ultra-portable devices that are user-operated and offer the ability to record ECGs regardless of location. Apple Watch Series 4 (AW4) and KardiaMobile 2-lead model (KM) are two of the most popular devices that are officially approved by the FDA. However, there is still a lack of knowledge regarding the AW4’s and KM's ability and accuracy to detect both sinus (SR) and atrial fibrillation (AF) rhythms in clinical situations. This paper aims to determine the practicality of using digital health devices, such as the AW4 and KM, in modern medical practice by assessing and comparing their accuracies in identifying heart rhythms and heart rate. A total of 200 patients, all of whom were scheduled for a visit to the at Toronto Heart Centre clinic were enrolled from Jan 2018 to Dec 2019. A 12-lead electrocardiogram (ECG) was obtained, followed by AW4 (WatchOS 5.3) and KM, within 5 minutes of one another. Each session with every patient consisted of an ECG recording from a 12-lead ECG, from KM's ECG function, from AW4’s ECG function (AECG), and a heart rate recording from AW4’s photoplethysmography function (APPG). Of the total 200 patients, the mean age was 63 years ± 15 and they were predominantly male at 59%. There were 162 (81%) patients who were in sinus rhythm and 38 (19%) who were in atrial fibrillation. Rhythm detection accuracies for sinus rhythm were: 100% for AW4 and 99.03% for KM, meanwhile those for Afib were: 90.48% for AW4 and 100% for KM. Heart rate accuracies for sinus rhythm were: 94.39% for KM, 90.65% for Apple PPG (APPG), and 96.26% for Apple ECG (AECG). Heart rate accuracies for Afib were: 91.30% for KM, 82.61% for AP, and 86.96% for AE. The results demonstrate that both AW4 and KM are highly capable in detecting rhythm and HR. There is a non-significant trend in favour of KM in rhythm detection and accuracy, compared with AW4. The difference is mainly due to artefacts (e.g. tremors) and strap size fitting for AW4.