A man in his 60s was admitted to the hospital for evaluation of abdominal pain. The patient had a medical history of hypertension and pacemaker implantation several years prior for symptomatic sinus node dysfunction. The patient related a history of regular pacemaker checks, during which he had been informed that his device showed normal function. During the hospitalization the patient experienced considerable heart rate fluctuation. The patient was asymptomatic with respect to his cardiovascular system. His cardiovascular physical examination was also unremarkable. An electrocardiogram (ECG) was obtained as part of his evaluation (Figure), and the inpatient cardiology service was consulted for concern that the patient’s pacemaker was malfunctioning.
Hornberger JW, Fentanes E, Gerasimon GG. Possible Device Malfunction in a Dual-Chamber Pacemaker. JAMA Intern Med. Published online July 24, 2017. doi:10.1001/jamainternmed.2017.2925