lead impedance
The electrical resistance of a pacemaker or ICD lead system, measured in ohms, indicating lead integrity and function.
Full Definition
Lead impedance represents the total electrical resistance encountered by current flowing through the pacemaker lead system, including the conductor, insulation, and electrode-tissue interface. Normal impedance values typically range from 300-1500 ohms depending on lead type and manufacturer specifications. Significantly low impedance may indicate insulation breach or conductor fracture, while extremely high impedance suggests complete circuit interruption or loose connections. Regular impedance monitoring during device follow-up visits helps identify lead problems before they result in loss of capture or inappropriate sensing, potentially preventing life-threatening complications in ICD patients.
Usage
Usage note: Always include units (ohms); distinguish from other electrical parameters like voltage or current.
In Context
- "Ventricular lead impedance increased to 2000 ohms, suggesting possible conductor fracture." — Device clinic alert report
- "All lead impedances remained stable within manufacturer specifications at 450-680 ohms." — Routine device check report