(FIT)-Module 5 Workshop 8: Device Cases-Ellenbogen Case 1 Answer

Video Transcription

Video Summary

The primary cause of inappropriate shocks in ICD lead failures is lead fracture, leading to over-sensing of rapid make-break potentials, not changes in impedance or thresholds. Typically, these fractures cause short R-R intervals or non-sustained tachycardia with non-physiologic intervals, affecting about 94% of patients. Sporadic electrical disconnections characterize the condition, often unnoticed in impedance tests. Despite stable RV pacing thresholds, intermittent variations may occur if measured during a disconnection. Importantly, lead fracture is not evidenced by noise on shock electrograms, highlighting morphological and amplitude variability without typical noise signatures.

Keywords

ICD lead failure

lead fracture

inappropriate shocks

over-sensing

non-sustained tachycardia