Advancing cardiovascular health: photoplethysmography as a tool for electrocardiogram signal acquisition

This invited commentary refers to ‘Patients' perspectives on integrating eHealth in regular care pathways for atrial fibrillation: evaluating photoplethysmography for remote self-assessment’, by M.J.W. van Mourik et al., https://doi.org/10.1093/eurjcn/zvae156. The last decade has witnessed a significant surge in the availability of health technology, particularly wearables such as smartphones, smartwatches, activity trackers, and eHealth applications.1–3 These devices, commonly referred to as wearables, have become integral to personal health monitoring. However, the utilization and interpretation of data collected from these devices for primary and secondary cardiovascular prevention remain ambiguous, with no established guidelines or recommendations.4–11 One of the key technologies used in wearables is photoplethysmography (PPG).4 Photoplethysmography sensors can be integrated into various devices like smartphones, wrist bracelets, armbands, or smartwatches.4–11 These sensors estimate heart rate (HR) by analysing the pressure pulse detected through changes in the LED light absorbed by the blood flowing through an artery. This non-invasive method provides continuous HR monitoring, which is crucial for cardiovascular health. The European Society of Cardiology (ESC) defines patient engagement as behaviours where patients take more responsibility for their healthcare, and healthcare professionals consider patients’ health needs.12 Novel models of care delivery such as integrated care contribute to this by providing a whole of systems approach to ensure the patient is placed at the centre of holistic care delivery.13 Wearable technologies can facilitate this process by enabling patients to self-monitor various health aspects and potentially improve health outcomes.12 Qualitative research, published in the current issue of the European Journal of Cardiovascular Nursing, investigating patients’ perspectives on PPG applications in atrial fibrillation demonstrated that patients were overall positive about the use of such technology through smartphone applications and incorporated in remote care approaches.14 Moreover, such approaches have the potential to improve motivation and adherence in using these technologies, resulting in patients being actively engaged in their care process and taking ownership of the (self)management of their condition.15 Traditionally, heart rhythm measurements were performed using medical-grade electrocardiogram (ECG) devices. However, the ESC 2020 guidelines have paved the way for incorporating single-lead ECGs from mHealth devices to diagnose atrial fibrillation (AF).1 Both the ESC guidelines and a consensus statement by the European Heart Rhythm Association (EHRA),3 in conjunction with the Heart Rhythm Society, recognize the potential of PPG-based mHealth devices combined with artificial intelligence for detecting and diagnosing AF. This marks a significant advancement in arrhythmia management. Despite the promising potential of PPG technology, its validation for diagnosing AF remains a challenge. The available data on PPG validation are limited and often affected by a high risk of bias. Most validation studies have been conducted in clinical centres under supervised conditions, which differ significantly from the real-world, ambulatory environments where these devices are typically used. The accuracy of PPG measurements tends to decrease in unsupervised settings due to artefacts. Numerous research studies have assessed the ability of PPG to screen for asymptomatic AF.4–11 However, there is a scarcity of data validating these measurements in real-world conditions. In 2022, the EHRA published a consensus statement3 acknowledging that PPG-based devices can be used for AF screening and monitoring. Nevertheless, the diagnosis of AF still requires confirmation with an ECG after initial screening or before monitoring with PPG. Cathal J. Breen (Writing—original draft [lead], Writing—review and editing [lead]) and Jeroen Hendriks (Writing—review and editing [supporting])