Monitoring for and Diagnosis of Lead Dysfunction.

The predominant structural mechanisms of transvenous lead dysfunction (LD) are conductor fracture and insulation breach. LD typically presents as an abnormality of electrical performance; the earliest sign usually is either oversensing or out-of-range pacing or shock impedance. Accurate diagnosis of LD requires discriminating patterns of oversensing and impedance trends that are characteristic of LD from similar patterns that occur in other conditions. Implantable cardioverter-defibrillators have advanced features to detect and mitigate the consequences of LD; these features operate both independently and in conjunction with remote monitoring networks.