Complete Heart Block Detected by Consumer-Facing Digital Health Technologies
James E. Ip
N Engl J Med 2025;393:2254
DOI: 10.1056/NEJMicm2510111
A 70-year-old man with hypertension and coronary artery disease presented to the emergency department with a several-hour history of shortness of breath and a slow heart rate. On the day of presentation, his commercial mattress — which included a ballistocardiographic monitoring feature — had alerted him that his average heart rate the night before during sleep (42 beats per minute) was lower than usual (78 beats per minute). Using his smartwatch and home blood-pressure machine, the patient had confirmed ongoing bradycardia. After also noting new exertional dyspnea, he had called his primary care doctor, who advised him to present to the emergency department. The patient’s heart rate was 40 beats per minute, and his blood pressure was 127/64 mm Hg. Physical examination was unremarkable except for bradycardia. A review of the heart-rate trend on the patient’s smartwatch showed a sudden decrease in the heart rate at 2 p.m. the day before presentation (Panel A). An electrocardiogram showed complete heart block with a junctional escape rhythm (Panel B). As consumer-facing digital health technologies become more popular, patients may seek physician input on the results. Although asymptomatic bradycardia during sleep is common, the sudden occurrence of unexpected, symptomatic bradycardia warrants evaluation, especially with confirmatory electrocardiography. After a dual-chamber leadless pacemaker was placed, the patient’s symptoms abated.
