Wearable saving lives: a case report.

Introduction: Unwitnessed cardiac arrests account for approximately half of all out-of-hospital cardiac arrests (OHCAs) and are associated with poor survival due to delayed recognition. Sudden physical collapse is a key characteristic of cardiac arrest and may be detected using accelerometer-based fall detection algorithms incorporated into commercial wearable devices. We report a case of unwitnessed OHCA in which smartwatch-based fall detection triggered automated alerts, resulting in timely initiation of cardiopulmonary resuscitation and favourable outcome. Case description: A 69-year-old man suffered an unwitnessed OHCA while running alone. Wearing an Apple Watch with fall detection activated, his collapse triggered automated alerts to emergency contacts and emergency medical services (EMS). Family members rapidly reached the patient, found him unresponsive, and initiated CPR approximately 6-7 min after collapse. EMS arrived shortly thereafter and documented ventricular fibrillation as the initial rhythm. Following advanced life support, return of spontaneous circulation was achieved. Hospital investigations revealed severe two-vessel coronary artery disease with an aberrant right coronary artery with interarterial course and prior infarctions in the RCA and LAD territories. The patient underwent coronary artery bypass grafting and received an implantable cardioverter-defibrillator for secondary prevention. The patient was discharged home 29 days later with complete neurological recovery. Discussion: This case illustrates the potential of wearable devices to serve as digital witness in otherwise unwitnessed cardiac arrests. It further highlights the promise of dedicated wearable cardiac arrest detection technologies that may reduce delays in recognition and treatment, thereby potentially improving survival and neurological outcomes.