Atrial fibrillation dominant frequency changes during ablation

Atrial fibrillation (AF) dominant frequency (DF) is thought to reflect the degree of organisation of underlying atrial activity (AA). Our aim was to assess the changes in DF stage by stage throughout AF ablation. 64-lead body surface ECG was undertaken in 4 patients during AF ablation procedures. After QRST subtraction, DF was obtained from spectral analysis of the lead exhibiting the largest AF component (A22). 28 recordings of 2 minute duration obtained between each ablation were analysed for within and between recording changes in DF. Mean (SD) within recording DF difference was -0.023 (0.12) Hz. Mean (SD) between recording DF difference was -0.036(0.11) Hz. Within- and between-recording DF differences were not significant (Kruskal-Wallis ANOVA, p>;0.05). This study shows that the changes in DF due to ablation could not be distinguished from the natural variability of the DF as measured by the within recording variability.