Abstract 2473: Regional Fractionation and Dominant Frequency in Persistent Atrial Fibrillation: Effect of Left Atrial Ablation and Evidence of Spatial Relationship
Introduction Catheter ablation for persistent atrial fibrillation (AF) remains challenging and debate surrounds the significance of
complex fractionated atrial electrograms (CFE) and
spectral characteristics of signals in the left atrium.
We examined regional properties of these 2 parameters before and after ablation.
Methods Patients undergoing catheter ablation of persistent AF using 3-dimensional navigation (Ensite NavX, St Jude Medical) were studied. Using an irrigated tip bipolar ablation catheter, point-by-point mapping of the left atrium was carried out using a 15 segment grid before and after left atrial ablation. Analysis was done on electrograms over 8s of continuous recording:
in the time domain as degree of fractionation (CFE-mean) using automated detection software and
in the frequency domain with Fast Fourier Transform to obtain regional Dominant Frequency (DF) and Organization Index (OI).
Results A total of 420 points were collected from 16 patients with persistent AF. Post-ablation data were not obtained in 4 patients who converted to atrial flutter during ablation. CFE-mean increased from 99±27 to 143±52 ms (mean±SD, p<0.001) and DF decreased from 6.0±0.7 to 5.4±0.7 Hz (p<0.001) after ablation. Mean OI was unchanged (0.26±0.06 before and 0.25±0.04 after ablation, p=0.7). There was a significant association between CFE-mean and DF (r = −0.42, p<0.001, Figure⇓).
Conclusion Left atrial ablation reduces global left atrial DF and decreases the degree of fractionation. Regions containing fractionated electrograms seem to harbour high frequency activation, suggesting that CFE and DF sites may be spatially related.