Optimizing Interelectrode Distance for Accurate Mapping of Postinfarct Scars: Insights on Electrogram Characteristics

Area of Science:

• Cardiovascular Electrophysiology
• Medical Device Technology
• Cardiac Scar Imaging

Background:

• Improving catheter mapping resolution for postinfarct scar is crucial.
• The optimal interelectrode distance for precise scar characterization remains undetermined.

Purpose of the Study:

• To evaluate how varying interelectrode distances affect ventricular scar electrograms.
• To determine the optimal distance for mapping myocardial infarction scar.

Main Methods:

• Swine models with healed myocardial infarction were mapped using a 48-electrode array.
• Mapping was performed at interelectrode distances of 1.2, 2.4, 3.6, and 4.8 mm.
• Analysis focused on voltage amplitude and near-field (NF) vs. far-field (FF) potential relationships.

Main Results:

• Closer distances (1.2 mm) initially correlated well with infarct size, but larger distances (4.8 mm) overestimated it.
• Adjusting voltage cutoffs restored correlation accuracy across distances.
• A 2.4 mm distance began to attenuate FF potentials, with optimal NF/FF ratios achieved at 2 mm (1.3 ± 0.3).

Conclusions:

• Bipolar configurations with a 2 mm interelectrode distance effectively delineate endocardial scar.
• This distance attenuates interfering near-field potentials, enhancing scar mapping accuracy.
• The benefits plateau at 2 mm, indicating it as the optimal distance for postinfarction substrate characterization.