Abstract 2515: Regularity and Centrifugal Dissipation of Frequency: Evidence that High-Frequency Sites are Drivers in Persistent Atrial Fibrillation
Introduction: Dominant frequency (DF) mapping during persistent atrial fibrillation (AF) identifies high-frequency atrial sites. Whether those sites play a mechanistic role in AF as drivers vs. a passive role due to shorter refractoriness is unknown.
Hypothesis: We hypothesized that high-frequency atrial sites represent AF drivers, and as such would be expected to show not only higher frequency, but also higher regularity and centrifugal decrease in frequency.
Methods: Nine pts with persistent AF (age 61 ± 11 yrs, 7 M) had 15-sec electrogram recordings at ≤10 sites in each atrium that were tagged on Carto prior to catheter ablation. DF and regularity index (RI) were determined for each site. Multiple linear regression was used to test correlation in the whole group between DF and RI and between DF and distance from maximum DF site.
Results: Mean DF and mean RI were higher in LA than RA (5.8 ± 0.6 vs 5.5 ± 0.7 and 0.55 ± 0.09 vs 0.49 ± 0.05, both p<0.05). Highest DF was in LA in all pts except one, whereas lowest DF was in RA in all pts except one. There was significant correlation between DF and RI. RI decreased by 0.067 for each decrease in DF of 1 Hz (R= 0.59, p<0.0001) (e.g. Fig⇓). Moreover, there was strong negative correlation between DF and distance from maximum DF site. DF decreased by 0.06 Hz per centimeter of distance from maximal DF site (R= −0.80, p<0.0001) (e.g. Fig⇓).
Conclusions: High-frequency sites, which are mostly seen in LA in persistent AF pts, manifest higher regularity and centrifugal dissipation of frequency. These findings suggest that high-frequency sites act as drivers in pts with persistent AF, and may have implications for target selection in ablation of AF.