What is a common sign of catheter lead fracture during device interrogation and how is it addressed?

• A. Gradual rise in impedance with loss of sensing
• B. Sudden drop in impedance with loss of sensing
• C. No change in impedance; replace device
• D. Sudden rise in impedance with loss of sensing/capture; replace or reposition the lead and recheck function

Answer: (D)

A lead fracture often shows up as an abrupt rise in impedance with loss of sensing and loss of pacing capture during device interrogation. When the conductor is broken, the circuit becomes open, so the impedance seen by the generator skyrockets. At the same time, the damaged lead can no longer reliably detect intrinsic cardiac signals or deliver pacing energy, so sensing amplitudes fall and pacing capture is lost. This combination—sudden impedance increase plus loss of sensing/capture—points to a discontinuity in the lead rather than gradual insulation wear or a short circuit, which tend to present differently.

The appropriate response is to address the faulty lead by replacing or repositioning it and then rechecking function. If a lead fracture is confirmed or highly suspected, salvaging the lead is often not feasible, so replacement or repositioning with subsequent verification of impedance, sensing, and capture is the standard course.