Wearable health devices are designed to be applied to the head (helmets, patches, glasses, earphones, earrings, headbands, and hearing aids), upper and lower limbs (smart watches, bracelets, shoes, and socks), and torso (belts, underwear, and suits). These devices can deliver information used by physicians and other health care professionals to collect epidemiological information and vital signs, prevent illnesses and complications, and diagnose and manage acute and chronic pathological conditions. Moreover, these devices can support rehabilitation of sports, cognitive dimensions, and disabilities [1], [2]. Wearable devices are rapidly spreading worldwide, and market forecasts indicate 520,000,000 devices will be sold by 2025 [3].

Smartwatches are wrist-mounted devices with computing capacity that can connect to other devices via short-range wireless networking. They are commonly used by the general population to monitor health status through specific applications, as they provide alert notifications and collect and store personal data through a variety of sensors [4]. Several companies are introducing smartwatches with health-monitoring applications that show multiple functions, such as sleep monitoring, blood oxygen saturation, electrocardiogram (ECG) sensors, fall detection, and heart health status monitoring [5]. Smartwatches can also be employed in psychiatric disorders because of their ability to collect biometric and behavioural data, which is useful for multimodal prediction systems of mental illness exacerbations [6].

Smartwatches are increasingly used to recognise the occurrence of heart rhythm alterations early, thus allowing the wearer to an early referral to hospitalisation in case of potentially severe conditions.

Despite their costs, smartwatch technologies that are specifically used in healthcare are rapidly spreading worldwide [2]. Currently, 210.18 million of persons use smartwatches, and this number is expected to increase to 229.51 by 2027 [7].

Smartwatches are currently used for different aspects related to the cardiovascular medicine, among which: risk calculation in patients or healthy persons; screening and diagnosis of cardiac dysrhythmia; acute coronary syndrome and long QT identification; cardiac telerehabilitation; management of hypertension; identification of electrolytic impairments; management of heart failure; drugs titration [8].

Recently, detection of atrial fibrillation (AF), based on heart rate monitored by optical sensors, was shown to be feasible and reliable using the Apple Watch® and its application. Indeed, the ECG function of the Apple Watch Ultra™ has been approved by the Food Drug Administration (FDA) for detecting the presence of AF. In a recent systematic review and metanalysis to evaluate the accuracy of smart wearables in detecting atrial fibrillation, smartwatches showed a sensitivity, specificity, and a receiver operating characteristic curve of 93 %, 94 % and 0.94, respectively, even if the heterogeneity among the studies was high (I2 = 91.7 %) [9].

There are already many other smartwatches and wearable devices alongside the Apple Watch® capable of recording a single-lead electrocardiogram, and it is reasonable to expect this technology to become a standard feature for all smartwatches, such as heart rate monitoring.

Previous case reports have shown the sensitivity of the Apple Watch® in highlighting morphological changes typical of acute coronary syndrome [10]. Indeed, implementing this feature on all smartwatches could potentially exert a great impact on patient outcomes with regard to the early detection of various heart diseases [10].

The present paper reports the case of a healthcare worker who, after experiencing chest symptoms, detected alterations in the ST segment of his own ECG using an Apple Watch®. These conditions prompted him to visit the hospital, where he was diagnosed with myopericarditis, allowing for rapid treatment and prevention of potential complications.