Gradually increasing pacing impedances with normal sensing values in pacemaker and defibrillation leads: A watchful...

The increasing prevalence of cardiac implantable electronic devices (CIEDs) has led to greater data collection, including pacing impedance, a key measure of lead integrity and electrical function. Although acute impedance changes may signal lead fractures or insulation defects, gradual increases are often linked to tissue-interface calcification. The optimal management of patients with progressively rising impedance remains uncertain.

This study aimed to assess the prevalence, clinical consequences, and management strategies for CIED leads showing a gradual increase in pacing impedance of >1200 Ω.

We conducted a single-center retrospective cohort study of 59 patients (42 with an implantable cardioverter-defibrillator and 17 with a pacemaker) over a median follow-up of 9.2 years (range 2.8-18.5). Data on patient demographics, device characteristics, and outcomes associated with elevated impedance were analyzed. Impedance values, intracardiac signals, and pacing thresholds were assessed at baseline and every 6 months up to 18 years.

Among patients with an implantable cardioverter-defibrillator, 33 of 42 leads (78.6%) were preserved, whereas 9 were replaced (5 prophylactically, 2 owing to oversensing, and 2 for threshold issues). In patients with a pacemaker, 12 of 17 leads (70.6%) were preserved, with 5 replacements (4 prophylactic and 1 for threshold issues).

A watchful waiting strategy seems safe for patients without sensing or threshold concerns and in the absence of a pacing indication. A patient-centered approach should guide the management of gradual impedance increases in CIED leads.