Unipolar Electrogram
An intracardiac recording obtained between a catheter electrode and a distant reference, providing broad spatial sensing and timing information.
Full Definition
A unipolar electrogram is recorded between a catheter electrode and a distant reference electrode, typically on the surface of the body or another catheter location. This configuration creates a large sensing field that detects electrical activity from a broader area compared to bipolar recordings. Unipolar electrograms provide excellent timing resolution for activation mapping and can detect signals from greater distances, making them useful for identifying breakthrough points and remote electrical activity. The broader sensing field makes unipolar recordings more susceptible to far-field signals and noise but valuable for understanding global activation patterns and wavefront propagation.
Usage
Usage note: Use 'unipolar' as adjective, 'electrogram' as noun. Avoid 'unipolars' as noun form.
In Context
- "Unipolar electrograms showed earlier activation at the epicardial breakthrough site." — Activation mapping study
- "The unipolar electrogram morphology suggested an epicardial origin for the VT." — Source localization report