Multichannel Smartwatch ECG vs Standard ECG for the Detection of ST-Segment Changes in ACS

person wearing a smartwatch
Smart watch showing pulse while doing sport in fitness studio.
Multichannel smartwatch ECG were found to be in agreement with standard ECGs for the detection of ST-segment changes in patients with acute coronary syndrome.

Multichannel smartwatch electrocardiogram (ECG) were found to be in agreement with standard ECGs for the detection of ST-segment changes in patients with acute coronary syndrome, according to a study published in JAMA Cardiology.

Researchers investigated the feasibility and accuracy of using a commercially available smartwatch for recording multiple ECG leads and detecting ST-segment changes associated with acute coronary syndromes compared with a standard 12-lead ECG. A total of 100 participants (mean age, 61±16 years; 67% men; n=54 with ST elevation myocardial infarction; n= 27 with non-ST elevation myocardial infarction; and n=19 healthy individuals) were enrolled.

An agreement between the smartwatch and standard ECG was observed for the identification of: a normal ECG (Cohen κ coefficient, 0.90; 95% CI 0.78-1.00), ST-segment elevation changes (Cohen κ coefficient, 0.88; 95% CI 0.78-0.97), and non–ST-segment elevation changes (Cohen κ coefficient, 0.85; 95% CI 0.74-0.96).

An agreement between smartwatch-obtained ECGs and standard ECGs was observed for detecting the amplitude of ST-segment changes (bias, −0.003±0.18; lower limit, −0.36; upper limit, 0.36). Use of the smartwatch for diagnosing normal ECG had an 84% sensitivity (95% CI 60%-97%) and a 100% specificity (95% CI 95%-100%). For ST elevation, sensitivity was 93% (95% CI 82%-99%) and specificity was 95% (95% CI 85%-99%).

Study limitations include the fact that detection of ST-segment abnormalities is not possible with a wrist smartwatch, as recording the ECG, except for lead I, requires removal of the watch and its placement in the appropriate chest and abdomen locations. In addition, interpretation of the ECG generated by the smartwatch in PDF format must be performed by a cardiologist.

“Every minute counts and 10 minutes or less is recommended from the first medical contact to recording of an ECG,” the study authors commented. “The smartwatch is not designed for clinical settings such as rapid triage, emergency department, ambulance, and fieldwork. However, the possibility that, under specific circumstances (eg, when the standard ECG is not available or during pandemics or catastrophes), a smartwatch can be used to recognize ST-segment changes with multichannel ECGs that could be of clinical and social relevance in individuals with chest pain,” they added. “The major findings of the present study were that a commercially available smartwatch allowed the possibility to obtain leads I, II, III, V1, V2, V3, V4, V5, and V6, and this watch was able to detect ECG changes similar to those noted with a standard 12-lead ECG in patients with acute coronary syndromes.”


Spaccarotella CAM, Polimeni A, Migliarino S, et al. Multichannel electrocardiograms obtained by a smartwatch for the diagnosis of ST-segment changes [published online August 31, 2020]. JAMA Cardiol. doi: 10.1001/jamacardio.2020.3994