Background: Atrial tachycardia (AT) is a commonly encountered rhythm disorder and most patients require catheter ablation. In this study, the aim was to evaluate the outcomes of catheter ablation in patients with symptomatic AT, define acute and long-term outcomes, and determine the clinical and electrophysiological features that affect these outcomes.

Methods: A total of 666 (mean age: 55 ± 16, gender: 344 (51.7%) female) symptomatic patients with AT were enrolled. Activation mapping was performed using 3-dimensional electroanatomical mapping as well as entrainment mapping when needed. Atrial tachyarrhythmia (ATa) recurrence was defined as the presence of atrial fibrillation or AT (≥ 30 seconds) detected by electrocardiogram, Holter, or implantable device interrogation.

Results: Macroreentry was the primary mechanism in right and left atrium (70.2% and 52.8%, respectively). Cavotricuspid isthmus dependent macroreentry was the most frequent mechanism in right ATs, whereas perimitral reentry and roof-dependent macroreentry were the most common mechanisms in left ATs. Acute procedural success was 96.3% after catheter ablation. Freedom from ATa was 72.8% after index procedure and
84.5% after multiple procedures during a mean follow-up of 39 ± 23 months. In multivariable Cox regression analysis, history of atrial fibrillation [HR: 2.43, 95% confidence interval (CI): 1.78-3.30; P < .001], previous cardiac surgery (HR: 1.68, 95% CI: 1.22-2.30; P = .001) and moderate to severe tricuspid regurgitation (HR: 1.47, 95% CI: 1.08-2.01; P = .014) were significant predictors of ATa recurrence.

Conclusion: The findings demonstrated that catheter ablation of tachycardia has a high acute success rate and favorable long-term outcomes in patients with symptomatic AT.