Leadless pacemaker tine fracture resulting in device migration to the pulmonary artery: A case report

A 96-year-old woman underwent implantation of a leadless pacemaker (Micra™ AV2; Medtronic, Inc., Minneapolis, MN, USA) for sick sinus syndrome. One month after implantation, pacing failure due to an elevated pacing threshold was observed, and the pacing output was increased. At routine follow-up one year after implantation, recurrent pacing failure was detected. Chest radiography revealed migration of the device into the left pulmonary artery. At least two of the four fixation tines were missing from the device body, and one fractured tine remained embedded in the right ventricular myocardium. Because the patient was asymptomatic, ventricular pacing dependency was low, and considering her advanced age and comorbidities, device retrieval or reimplantation was not performed. Although leadless pacemakers reduce complications associated with conventional transvenous systems, device-specific mechanical complications have been reported. We present a rare case of tine fracture of a Micra™ AV2 device resulting in migration into the pulmonary artery.

Tine fracture is a rare but potentially serious mechanical complication of leadless pacemakers. When pacing thresholds increase or pacing failure occurs, careful assessment of device position and fixation, including detailed imaging review, is essential.