Using a smartwatch electrocardiogram to detect abnormalities associated with sudden cardiac arrest in young adults
Sudden cardiac arrest (SCA) and its most common consequence, sudden cardiac death (SCD), remain major public health problems, accounting for approximately 50% of all cardiovascular deaths.1 Preventing SCD is challenging in part because in more than 25% of victims, it represents a first symptomatic cardiac event.1 Compounding this is the estimated 10% survival rate for out-of-hospital cardiac arrest.1 Whereas coronary artery disease is the predominant cause of SCD in elderly individuals, more varied diagnoses account for SCD in young adults, including cardiomyopathies, channelopathies, and accessory pathways.2,3 The surface 12-lead ECG can readily enable the detection of prolonged QT intervals, Brugada patterns, and ventricular pre-excitation, and may trigger further investigations to assess for hypertrophic cardiomyopathy (HCM) and arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVC/D).4–10 However, in general, 12-lead ECGs are not widely performed in young asymptomatic adults. The widespread and growing use of contemporary smartwatches may provide alternative diagnostic opportunities by permitting consumers to self-register ECGs and to digitally send them to healthcare providers.11 Rapid access to ECG recordings, without a physician’s order, could facilitate screening efforts and could empower individuals to play a more active role in their health care. Indeed, this technology has shown considerable promise for atrial fibrillation screening.12 However, a major technical limitation of smartwatch ECGs is that they are typically worn on the left wrist—a position in which only lead I is recorded. To better detect ECG abnormalities associated with SCA, additional recordings recreating precordial leads may be required.