In persistent AF patients, increased rapid activity on the posterior wall is linked to distinct posterior wall flattening and reduced protrusion near left pulmonary veins, suggesting PW geometry as a
Does left atrial posterior wall geometry correlate with the frequency of pivoting and rotational propagation patterns in patients with persistent AF?
Increased flattening of the left atrial posterior wall is associated with a higher frequency of pivoting and rotational propagation patterns, suggesting posterior wall geometry could serve as a pre-procedural imaging marker to identify candidates for posterior wall isolation.
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Abstract Background Rapid posterior wall (PW) activity during atrial fibrillation (AF) has been linked to improved outcomes with posterior wall isolation (PWI) in addition to pulmonary vein isolation in persistent AF patients 1. Identifying candidates for PW isolation using non-invasive methods could enhance procedural planning. Purpose This study investigates the relationship between left atrial PW geometry and the frequency of pivoting and rotational propagation patterns, a surrogate for rapid PW activity, as identified through charge density mapping (CDM) during AF. Methods Thirty-five persistent AF patients underwent de novo AF ablation guided by CDM. Left atrium reconstructions were generated using intra-chamber ultrasound. Non-contact intra-chamber voltage measurements were recording during 20 seconds of AF prior to ablation, and used to derive propagation. Pivoting and rotational propagation patterns 2 were quantified in frequencies per second for each of the ~3000 vertices comprising a patient’s geometry. Posterior wall (PW) regions were automatically identified using a MATLAB-based approach. For each patient, the median frequency of propagation patterns on the PW was calculated (Figure 1A). Patients were then classified into two cohorts based on whether this frequency was above (frequency+) or below (frequency-) the population median. A point distribution-based statistical shape model was created using ShapeWorks 3, with each geometry represented by 512 correspondence points (Figure 1B). Procrustes scaling was applied to remove overall scale from the model. The mean shape for each cohort was calculated to visualise group differences, and the significance of differences in correspondence point locations assessed using Hotelling T2-test with false discovery rate correction. Results The frequency+ cohort (16 patients) and frequency- cohort (19 patients) exhibited similar demographics (proportion male gender: 81% vs. 68%, p=0.39; median age: 56 years vs. 65 years, p=0.17; median BMI: 30kg/m2 vs. 31kg/m2, p=0.98; median CHA₂DS₂-VASc: 1.5 vs. 2, p=0.54). The frequency- cohort had a significantly larger mean left atrial volume (176 ml vs. 147 ml, p0.05). The mean left atrial geometry of the frequency+ cohort demonstrated increased flattening of the PW compared to the frequency- cohort (Figure 1C). This was primarily mediated by significantly reduced protrusion of the PW around the left sided pulmonary veins (Figure 2). Conclusion An increased frequency of pivoting and rotational propagation patterns on the PW is associated with distinct geometric features, suggesting that PW geometry could serve as a valuable pre-procedural imaging marker for identifying candidates for PW isolation. This approach has the potential to eliminate the need for additional mapping during AF, thereby streamlining catheter ablation procedures and enhancing overall efficiency.
Sharp et al. (Sat,) reported a other. In persistent AF patients, increased rapid activity on the posterior wall is linked to distinct posterior wall flattening and reduced protrusion near left pulmonary veins, suggesting PW geometry as a .