Correlation of unipolar electrogram modification with ablation index during pulmonary vein isolation: A pilot study

Area of Science:

• Electrophysiology
• Cardiology
• Medical Devices

Background:

• Pulmonary vein isolation (PVI) via radiofrequency catheter ablation is standard for drug-refractory atrial fibrillation.
• Transmural lesion formation during PVI is indicated by eliminating the negative component of the local unipolar electrogram (UEGM).
• Ablation Index (AI) predicts ablation lesion quality, suggesting combined UEGM and AI could enhance PVI safety and efficiency.

Purpose of the Study:

• To investigate the correlation between UEGM modification characteristics in different left atrial target areas and their associated AI values during PVI.

Main Methods:

• Analysis of 10 patients undergoing PVI using radiofrequency energy.
• Collection of local electrophysiological properties and ablation parameters from 15 designated left atrial areas.

Main Results:

• Six male patients (mean age 66) with 80% paroxysmal AF were studied.
• UEGM modification occurred faster in the posterior wall (8.9s) than the anterior wall (11.1s).
• UEGM modification was achieved at significantly lower AI values than conventional AIs (p < .001).

Conclusions:

• Ablation Index (AI) values derived from local UEGM modification during PVI are shorter than conventionally recommended values.
• Conventionally recommended AIs may be safely reduced, ensuring PVI efficacy and lesion quality.
• This optimized AI approach could potentially decrease the risk of collateral thermal injuries.