Characterization and anatomical distribution of AF driver sources identified by the novel Ockham AF mapping module

Abstract

Aims: The Ockham AF Mapping module is a novel mapping system that identifies atrial fibrillation(AF) drivers based on short cycle lengths and localized continuous activation. This study aimed to validate the characteristics of AF drivers identified by the novel module.

Methods and results: This retrospective multicenter study enrolled 110 consecutive patients with AF who underwent ablation using the Ockham module. AF drivers were defined by a short Local Cycle Length (CL) ≤ the median of the minimum and peak CL, and a high Duty Cycle (the ratio of the electrical activation time to the Local CL) of ≥80%. A total of 112,388 beats were analyzed, identifying 517 highlighted driver areas in 226 atria. Due to inconsistent AF activation, the module could not analyze a median area of 11.9(3.6-19.0) cm² per atrium, most frequently in the septal region. The median peak CL was 146(135-161) ms and was significantly shorter in the left atrium (LA) than the right atrium (RA). Following pulmonary vein isolation, the CL increased significantly in the LA but not in the RA. The module highlighted a median driver area of 11.0(6.8-18.9) cm² per atrium. These areas were located most commonly in the posterior and inferior regions of the LA and the lateral region of the RA. Notably, the dominant CL of the highlighted areas showed a significant correlation with the severity of rotational activation identified by another phase-mapping system.

Conclusions: The Ockham AF Mapping module reliably identified AF drivers, characterized by short Local CL and high Duty Cycle.

Keywords: Atrial fibrillation; Atrial fibrillation drivers; Catheter ablation; Ockham AF module.