Abstract 3368: Spectral Characteristics and Long-Term Outcome After Real-Time High-Frequency Sites Ablation in Atrial Fibrillation
Online spectral analysis and radiofrequency (RF) ablation of dominant frequency (DF) sites terminates atrial fibrillation (AF) during the procedure in a significant proportion of paroxysmal AF patients. We aimed to assess the clinical long-term effect of ablation in relation to the spectral characteristics of AF.
Methods & Results: We performed RF ablation of primary (highest) and secondary (2nd higher) DF sites in 37 pts (23 paroxysmal, 14 chronic AF). The effect of ablation was assessed evaluating AF termination and changes in DF in left (LA) and right atrium (RA) and the coronary sinus (CS). AF terminated during ablation in 74% paroxysmal AF vs 7% chronic AF (p<0.001) pts. In paroxysmal AF patients, ablation significantly reduced DF (Hz) in the LA (7.1±1.1 vs 5±0.9, p<0.001) abolishing baseline left-to-right DF gradient (1.9±1.5 vs 0.6±0.3; p<0.001). In chronic AF patients, ablation reduced DFs both in LA and RA (LA 7.6±1 vs 6.4±0.9, p<0.01; RA 6.6±1 vs 6.1±0.9; p<0.01). After a mean follow-up of 7.21±4.3 months, 70% of paroxysmal and 43% chronic AF pts were free of AF symptoms without antiarrhythmic treatment. Sinus rhythm conversion during ablation did not predict a better long-term outcome, both in paroxysmal and chronic AF. There were no significant differences in DF reduction after ablation in paroxysmal AF pts that remained in SR vs AF during follow-up. In contrast, the reduction in DFs after ablation was associated with a higher probability of long-term SR maintenance in chronic AF pts.
Conclusions: In paroxysmal AF, ablation of DF sites terminates a significant proportion of AF episodes but AF termination during the procedure does not predict long-term outcome. Elimination of DF sites in chronic AF pts was associated with a better outcome, despite the absence of SR conversion during the procedure. Online DF mapping is a useful approach to effectively guide ablation therapy in AF.