Criteria for local myocardial electrical activation: effects of electrogram characteristics

Area of Science:

• Cardiology
• Electrophysiology
• Biomedical Engineering

Background:

• Detecting local myocardial electrical activation via extracellular recordings is often hindered by polyphasic electrograms.
• Distinguishing local activation from nonlocal activity is crucial for accurate electrophysiological assessment.

Purpose of the Study:

• To compare the efficacy of various signal variables in differentiating unipolar deflections caused by local activation versus nonlocal activity.
• To identify optimal criteria for detecting local activation in different cardiac signal populations.

Main Methods:

• Utilized a model of polyphasic deflections derived from atrial recordings during reentrant tachycardia.
• Assessed variable performance using areas under receiver operating characteristic curves.
• Identified optimal thresholds by maximizing statistics that corrected for pretest probability of local activation.

Main Results:

• The greatest negative first derivative of unipolar potential best discriminated local from distant ventricular signals.
• The ratio of the first derivative to the potential outperformed the greatest negative first derivative for distinguishing local atrial from distant ventricular signals.
• A linear combination of potential and its first derivative-to-potential ratio showed robust performance across all signal types.

Conclusions:

• Optimal criteria for detecting local myocardial activation are signal population-dependent.
• A statistical approach can successfully identify optimal detection criteria for specific signal populations.