unipolar lead
A cardiac lead configuration with one electrode at the tip, using the pulse generator case as the return electrode.
Full Definition
A unipolar lead system consists of a single electrode positioned at the lead tip in contact with cardiac tissue, with the electrical circuit completed through the metallic case of the pulse generator serving as the return electrode. This configuration creates a larger sensing area compared to bipolar leads, making it more sensitive to cardiac signals but also more susceptible to electromagnetic interference and muscle artifacts. Unipolar leads are less commonly used in modern devices due to their increased susceptibility to oversensing.
Usage
Usage note: Distinguish from 'monopolar' which refers to electrocautery configuration, not cardiac leads.
In Context
- "The unipolar lead configuration showed increased susceptibility to myopotential interference." — Electrophysiology study report
- "Conversion from unipolar to bipolar sensing eliminated the oversensing episodes." — Device programming note