A critical decrease in dominant frequency and clinical outcome after catheter ablation of persistent atrial fibrillation

BACKGROUND Termination of persistent atrial fibrillation (AF) by radiofrequency ablation (RFA) is associated with a high probability of freedom from AF but requires extensive ablation and long procedure times. OBJECTIVE The purpose of this study was to determine whether a critical decrease in the dominant frequency (DF) of AF is a sufficient endpoint for RFA of persistent AF. METHODS Antral pulmonary vein isolation (APVI) followed by RFA of complex fractionated atrial electrograms (CFAEs) in the atria and coronary sinus was performed in 100 consecutive patients with persistent AF. The DF of AF in lead V1 and in the coronary sinus was determined by fast Fourier transform (FFT) analysis at baseline and before termination of AF to identify a critical decrease in DF predictive of sinus rhythm after RFA. RESULTS A >= 11% decrease in DF had the highest accuracy in predicting freedom from atrial arrhythmias, with a sensitivity of 0.71 and a specificity of 0.82 (P <.001). At a mean follow-up of 14 +/- 3 months after one ablation procedure, sinus rhythm was maintained off antiarrhythmic drugs in 8/35 (23%) and 20/26 (77%) of patients with a <11% and >= 11% decrease in DF, respectively (P <.001). Sinus rhythm was maintained in 24/39 patients (62%) in whom RFA terminated AF. The duration of RFA and total procedure time were longer in patients with AF termination (95 +/- 23 and 358 +/- 87 minutes) than in patients with a >= 11% decrease in the DF (77 +/- 16 and 293 +/- 70 minutes) or >= 11% decrease in DF (80 +/- 17 and 289 +/- 73 minutes), respectively (P <.01). Among the variables of age, gender, left atrial diameter, duration of AF, left ventricular ejection fraction, duration of RFA, a >= 11% decrease in DF, and termination of AF, a >= 11% decrease in DF (odds ratio = 9.89, 95% confidence interval [CI] 2.84-34.47) and termination during RFA (OR = 4.38, 95% CI 1.50-12.80) were the only independent predictors of freedom from recurrent atrial arrhythmias. CONCLUSION In a retrospective analysis of consecutive patients with persistent AF, a decrease in the DF of AF by 11% in response to APVI and ablation of CFAEs was associated with a probability of maintaining sinus rhythm that was similar to that when RFA terminates AF.