Wearable Biosensors in Pediatric Cardiovascular Disease

earable biosensors gather continuous physiological data (CPD) in real time, generating information reflecting the patient's current state.The paradigm of using CPD to guide clinical decisions is expected to be a major advance for patients with chronic diseases like congenital heart disease (CHD), and form part of the evolution from episodic to continuous patient care.In adult cardiovascular populations, there is already growing evidence of the benefit of mobile health technologies.However, most mobile health technologies, especially wearable biosensors, are not designed for children, despite numerous specific pathologies that could benefit from this technology.One key driver for the development of wearable biosensors is the potential to use CPD to generate real-time, clinically actionable insights from predictive analytics that include early warnings of clinical deterioration and prompts for behavioral changes (Figure).The advent of machine learning methods that can detect subtle patterns from large sets of CPD may make this achievable.Where might CPD have a role in pediatric cardiology?Patients with singleventricle heart disease who are between the first and second stages of surgical palliation (the interstage period) have high morbidity (eg, unplanned readmissions and catheter interventions) and mortality.In the intensive care unit setting, retrospective analysis of ECG tracings predicted cardiopulmonary arrest in this population.1 Interstage patients' high morbidity and mortality continue after discharge, so perhaps wearable CPD and predictive analytics could be used to predict these events at home.Likewise, more oxygen saturation data points may allow better informed timing of the second and third stages of single-ventricle palliation.Malignant arrhythmias in high-risk populations such as intra-atrial reentrant tachycardia in older patients who underwent the Fontan procedure, ventricular tachycardia in patients who have tetralogy of Fallot with wide QRS, and sudden death in long-QT syndrome present additional targets for continuous monitoring with wearables, although clinical effectiveness is yet to be proven.Even longerterm deterioration detection for patients with heart failure, through monitoring tachypnea, tachycardia, and weight gain, may be amenable to detection with wearables in children as it is in adults.Given the high rates of obesity and cardiometabolic risk factors in children, another key potential use for wearables is early intervention to prevent atherosclerotic cardiovascular disease in adulthood.Here, the focus so far has been on step counters to encourage physical activity.Systematic reviews suggest that mobile health interventions have a small but significant effect to increase physical activity and may improve dietary intake. 2 Of course, there is no guarantee that wearables improve outcomes: a large randomized trial in adults showed that a wearable device in addition to weight counseling actually led to decreased weight loss.3 More data are needed to see whether wearables have a beneficial impact on downstream risk factors in youth.