Intraprocedural atrial tachycardia during ablation of paroxysmal atrial fibrillation: incidence, mechanisms, and clinical outcomes.

BACKGROUND

Radiofrequency catheter ablation (RFCA) is the mainstay treatment for paroxysmal atrial fibrillation (PAF). However, the incidence, risk factors, and impact of intra-procedural atrial tachycardia (IAT) during PAF ablation remain insufficiently characterized. The purpose of this study was to explore the incidence, risk factors, electrophysiological features, and clinical outcomes of IAT.

METHODS

In this single-center, prospective study, 255 patients undergoing RFCA for PAF were analyzed. IAT was defined as stable tachycardia lasting more than 2 min, either induced or spontaneous. Logistic regression identified risk factors for AT, and Kaplan-Meier analysis was used to examine its impact on long-term success.

RESULTS

IAT occurred in 13.33% of patients. Right atrial enlargement was identified as an independent risk factor [odds ratio (OR) = 1.14, P = 0.015], and AT involving the peri-tricuspid (45%), peri-mitral (45%), roof-dependent (2.5%) and focal (7.5%) types were found. The overall 12-month sinus rhythm maintenance rate was 78.0%, with no significant difference between the AT and non-AT groups (79.4% vs. 77.8%, P = 0.84).

CONCLUSIONS

IAT was observed in 13.3% of patients undergoing PAF ablation, with macro-reentrant circuits around the tricuspid and mitral annuli being the primary mechanisms. Right atrial diameter served as a key predictor. Our data demonstrate that with successful intra-procedural identification and targeted ablation, IAT patients can achieve a 12-month prognosis similar to non-IAT patients.