Accuracy of Smartwatch Electrocardiographic Recording in the Acute Coronary Syndrome Setting: Rationale and Design of the ACS WATCH II Study.

Background: Acute Coronary Syndrome (ACS), with or without ST-segment elevation, is a major contributor to global mortality and morbidity. Swift diagnosis and treatment are vital for mitigating cardiac damage and improving long-term outcomes. The 12-lead electrocardiogram (ECG) currently serves as the gold standard for diagnosis in ACS with ST-segment elevation and may support the diagnosis in ACS without ST-segment elevation. However, the growing prevalence of smartwatches enables the acquisition of electrocardiographic data without traditional ECG equipment. While smaller studies support smartwatch ECG use, larger-scale validation within ACS remains lacking. The ACS WATCH II study aims to validate smartwatch ECG recordings for ACS. Methods: The primary objective is to validate smartwatch-obtained electrocardiographic data in patients presenting with ACS. Two cohorts of 120 patients each, presenting ACS with and without ST-segment elevation, will be assessed. Smartwatches will capture recordings of leads I, III, and V2 alongside standard ECGs. These leads, chosen due to a 97% ACS diagnosis sensitivity in previous studies, will undergo blind evaluation by two experienced external assessors against conventional ECG. Additionally, a control sample of 60 healthy individuals will be included. Conclusions: ACS WATCH II pioneers large-scale prospective validation of smartwatch ECG recordings in ACS patients. Additionally, it indirectly validates a swift diagnostic approach using three leads (I, III, and V2). This could expedite time-critical ACS diagnoses and simplify access through smartwatch-based diagnosis.

Smartwatch: Looking beyond what you see.

BACKGROUND: The clinical utility of the Apple Inc.® smartwatch in scenarios beyond detecting atrial fibrillation has been debated. Although the device has the capability to record electrocardiograms (ECG) and detect arrhythmias, voltage limitations hinder its accuracy in measuring real voltage when recording precordial leads. This limitation poses challenges for its clinical use in diagnosing ischemia and screening cardiomyopathies. This review aims to analyze the ECG recording capacity of the Apple Watch, investigate the reasons for voltage limitations, and explore alternative approaches for its use in these clinical scenarios. METHODS: A comprehensive literature review was conducted to examine the ECG recording capacity of the Apple Watch and the limitations encountered when recording precordial leads. Data in CSV format files were analyzed to gain insights into the underlying causes of voltage limitations. RESULTS: The Apple Watch demonstrates effectiveness in detecting cardiac arrhythmias such as atrial fibrillation using photoplethysmography and ECG recording. However, voltage limitations during precordial lead recordings impede accurate voltage measurement, thereby limiting its clinical utility. Analysis of the data stored in the CSV files revealed that these voltage limitations are primarily attributed to the presentation format. Exploring alternative approaches for data processing could potentially overcome this challenge. CONCLUSIONS: This review highlights the potential for addressing voltage limitations through alternative data processing approaches. Further research is necessary to identify suitable alternatives that enable the Apple Watch to be effectively utilized in these clinical scenarios.

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.