Lesion Sequence and Catheter Spatial Stability Affect Lesion Quality Markers in Atrial Fibrillation Ablation

Abstract

Objectives: This study sought to analyze high-frequency catheter excursion in relation to lesion quality markers in 20 consecutive patients undergoing first-time radiofrequency (RF) ablation for paroxysmal atrial fibrillation (AF).

Background: Ablation therapy for AF requires the delivery of durable lesions. The extent to which lesion sequence, catheter spatial stability, and anatomic location influence lesion formation during RF ablation of AF is not well understood.

Methods: Three-dimensional spatial excursion of the ablation catheter sampled at 60 Hz during pre-specified pairs of RF lesions was extracted from the CARTO3 System (Biosense Webster Inc., Irvine, California) and analyzed by using custom-developed MATLAB software (MathWorks, Natick, Massachusetts) to define precise catheter spatial stability during RF ablation. Ablation parameters including bipolar electrogram amplitude reduction, impedance decline and transmurality-associated unipolar electrogram (TUE) as evidence of lesion transmurality during lesion placement were recorded and analyzed.

Results: We collected 437,760 position data points during lesion placement. Ablation catheter spatial stability and lesion formation parameters varied considerably by anatomic location. Lesions placed immediately had similar bipolar electrogram amplitude reduction, smaller impedance decline, but higher likelihood of achieving TUE compared to delayed lesions. Greater catheter spatial stability correlated with lesser impedance decline.

Conclusions: Lesion sequence, ablation catheter spatial stability, and anatomic location are important modifiers of RF lesion formation. Lesions placed immediately are more likely to exhibit TUE. Greater ablation catheter stability is associated with lesser impedance decline but greater likelihood of TUE.

Keywords: ablation; excursion; impedance; sequentiality; stability.