Unipolar voltage mapping to predict lesion durability during pulsed field ablation

Area of Science:

• Electrophysiology
• Cardiovascular Ablation Technologies
• Biomedical Engineering

Background:

• Unipolar electrograms (u-EGMs) show promise for assessing lesion durability following pulsed field ablation (PFA).
• Validating u-EGM parameters is crucial for reliable assessment of PFA outcomes.

Purpose of the Study:

• To validate voltage thresholds on u-EGMs indicative of PFA-induced lesions.
• To determine the predictive value of these u-EGM changes for long-term lesion durability.

Main Methods:

• Patients undergoing PFA with a pentaspline catheter had unipolar and bipolar voltage maps acquired.
• Correlation analyses (ROC) were performed between u-EGM S-wave loss and unipolar voltage.
• Lesion durability was assessed in relation to unipolar voltage, and esophageal EGMs served as surrogates.

Main Results:

• A unipolar voltage threshold of ≤ 0.4 mV accurately predicted S-wave loss, signifying durable "core" lesions.
• Halo regions with higher voltages showed potential for recovery; double PFA applications yielded larger, more durable lesions.
• Unipolar voltage ≥ 0.4 mV in redo procedures predicted conduction recovery, indicating areas of incomplete ablation.

Conclusions:

• A unipolar voltage ≤ 0.4 mV combined with loss of the terminal S wave on u-EGM reliably identifies durable ablation regions.
• Unipolar mapping offers valuable insights into PFA lesion durability and can guide procedural optimization for enhanced efficacy.