Smartwatch ECG Tracing and Ischemic Heart Disease: ACS Watch Study

Background: Smartwatches have become a widely used tool for health self-care. Its role in ischemic heart disease (IHD) has not been assessed. Objetcive: The aim of this study was to evaluate the usefulness of smartwatch ECG registry in IHD. Methods: We present an observational study of 25 consecutive patients with acute IHD. Conventional ECG and smartwatch tracing were obtained simultaneously at admission. Waves of conventional and smartwatch ECGs were objectively compared. A survey on medical attitude was conducted among 12 physicians (3 cardiologists, 3 intensivists, 3 emergency physicians, and 3 general practitioners) and a score (1–5) of concordance between the records was requested. Results: There were no differences in Q-wave, R-wave, ST segment, or T-wave. There was a very strong correlation between ST segments, a strong correlation in Q-waves and R-waves, and a moderate correlation in T-wave measurements. All specialists obtained a high level of agreement (4.45 ± 0.45). Smartwatch tracings would lead to similar management compared to conventional ECG. There were only 6 (2%) discrepant cases due to differences in inferior repolarization, showing an almost perfect agreement (kappa = 0.96). Conclusions: In most patients with acute IHD, smartwatch ECG tracing is a reliable tool to make the diagnosis and guide appropriate medical care. However, due to their intrinsic limitations, inferior myocardial infarctions may be missed and require a conventional 12-lead ECG to rule them out.