Radiofrequency ablation of paroxysmal atrial fibrillation: factors determining long-term clinical efficacy. 
Most of the studies on this subject have reported predictors of recurrence of atrial fibrillation after catheter ablation with relatively short follow-up periods.  To retrospectively evaluate predictors of long-term recurrence of paroxysmal atrial fibrillation (AF) in patients undergoing pulmonary vein isolation following one single procedure.  The authors studied a total of 139 patients (102 men; mean age of 55 +/- 12 years) undergoing radiofrequency ablation using the ostial or extra-ostial techniques for left atrial approach, combined or not with cavotricuspid isthmus ablation (CTI).  Pre, intra and post-ablation variables were evaluated using univariate and multivariate analyses to determine the predictors of recurrence of AF after one procedure.  After a 33 +/- 12-month follow-up, we observed that a longer time of history of AF, use of more antiarrhythmic drugs, and recurrence of AF within 60 days post-procedure increased the risk of long-term recurrence of AF.  On the other hand, the association of atrial flutter and concomitant CTI ablation reduced the risk of recurrence of AF.  Clinical variables such as time of history of AF and a larger number of antiarrhythmic drugs already used influenced the outcomes of catheter ablation.  In patients with associated atrial flutter, simultaneous CTI block significantly reduced the long-term recurrence of atrial fibrillation.