Outcomes after radiofrequency catheter ablation of atrial tachycardia.

The purpose of this study was to evaluate the efficacy, safety, and clinical benefit of radiofrequency catheter ablation (RFCA) in a large series of patients with atrial tachycardia (AT). The determinants of success or failure of RFCA in AT remain unclear. We evaluated the results of radiofrequency ablation in 73 women and 32 men (mean age 48 +/- 19 years) with AT. Mapping techniques were based on identification of the earliest endocardial atrial electrogram recorded during AT. AT originated from the right atrium in 91 patients and from the left atrium in 14. The cardiac ventricles were dilated in 12 patients. AT ablation was successful in 80 patients (77%) regardless of the site of origin. Age, gender, rate of tachycardia, temperature achieved during application, or presence of tachycardiomyopathy were not significant determinants of acute success by univariate analysis. There was a significantly higher acute success rate of ablation in patients with paroxysmal (88%, 45 of 51) and permanent (71%, 30 of 42) forms than in patients with repetitive forms of AT (41%, 5 of 12) (p <0.005). The mean local endocardial electrogram time (relative-to-surface P-wave onset) was -47 +/- 17 ms at successful ablation sites and -29 +/- 21 ms at unsuccessful sites (p <0.03). Ablation was unsuccessful in 25 cases. Thus, RFCA of AT can be performed with a high acute success rate. Patients with repetitive forms and those with multifocal origin had a lower acute success rate. The highest incidence of recurrences was found in anterior right atrial foci.