Abstract 16967: Effect of Catheter Ablation of Persistent Atrial Fibrillation on Surface Atrial ECG Dominant Frequency

Abstract

Background: There are no standard techniques to track effects of catheter ablation (CA) of persistent atrial fibrillation (PeAF). The Atrial ECG (A-ECG) derived from the standard ECG provides the atrial dominant frequency (DF), an estimation of atrial rate. Research Question: Does CA for PeAF diminish A-ECG DF? Aims: To evaluate change in A-ECG peak DF pre- and post-CA. Methods: We obtained 1-minute epochs of surface ECG pre- and post-CA in 32 patients (age 63±9 years; 71% males) undergoing CA for PeAF. A-ECG was derived by QRST subtraction and independent component analysis filtering, and divided into overlapping10-second windows, each subjected to Fast Fourier Transform. DF was calculated for each lead as the average DF for all 10-sec segments. Peak A-ECG DF was assessed by regional lead group and among all leads. 10 patients were excluded for significant artifact. Of the 22 analyzed patients, all had pulmonary vein isolation and 3 had posterior wall isolation. Two-year outcomes were available in 20 patients (13 were free from recurrent AF). Results: The figure shows the change in the time-frequency plot (left panel) of DF for one subject and the shift in the spectra (right panel) with CA. A-ECG peak DF was significantly lower post- versus pre-CA: 5.96±0.63 vs 6.16±0.64 Hz, p=0.0009. By lead group, peak DFs were all lower post CA - Anterior (V1-3): 5.94±0.62 vs 6.13±0.64 Hz, p=0.0015; Inferior (II, III, aVF): 5.82±0.63 vs 6.01±0.66 Hz, p=0.0040; Lateral (I, aVL, V5-6): 5.82±0.64 vs 5.99±0.63 Hz, p=0.0015. In this small cohort, there was no significant difference in change of peak DF in those free from AF versus with recurrent AF (-2.4±4.3% vs -4.6±3.7%, p=0.26). Conclusion: The A-ECG provides physiologic information of activation rate in PeAF, but despite current, advanced signal processing techniques is analyzable in only 69% of patients. CA results in a significant reduction in DF. Clinical implications of these CA induced changes require further study.