Single-centre experience on persistent atrial fibrillation termination using a dual-energy lattice-tip catheter

Background

Catheter ablation is an effective treatment for atrial fibrillation (AF). Intraprocedural arrhythmia termination may occur through three mechanisms: direct conversion to sinus rhythm (SR), transition to a regular atrial tachycardia/flutter that subsequently organizes into SR, or restoration of SR following direct-current cardioversion. Previous studies have shown that spontaneous restoration through the first two mechanisms is associated with lower AF recurrence within the first year.

Purpose

To assess whether ablation with a dual-energy, lattice-tip catheter is associated with a higher rate of intra-procedural SR restoration compared with radiofrequency ablation reported in the literature, and to identify the anatomical regions most frequently involved in AF termination.

Methods

In this retrospective, single-center observational study, 27 consecutive patients (18 male, 66%; mean age 63.7 ± 13 years) undergoing catheter ablation for persistent AF with the dual-energy lattice-tip catheter were included. Patients were divided into two groups: the interrupted group, in which AF terminated during energy delivery, and the non-interrupted group, in which cardioversion was performed at the end of the procedure; the anatomical sites associated with arrhythmia termination were recorded.

Results

Baseline clinical and echocardiographic characteristics did not differ between patients with intra-procedural AF termination and those requiring external cardioversion (Table 1). Procedural characteristics were also comparable (Table 2), with all patients receiving extra–pulmonary vein lesions targeting the roof and posterior wall, and no group differences in the number of additional extra-pulmonary foci treated. No major complications occurred; two minor complications occurred: coronary artery spasm during mitral isthmus ablation resolved with intravenous nitroglycerin.

Although not statistically significant, patients with AF termination during energy delivery experienced no in-hospital recurrences, whereas those without termination had a 25% in-hospital recurrence rate. Termination sites included the pulmonary veins (n=2, 18%), the inferior portion of the posterior wall during homogenization (n=6, 55%), the anterior wall (n=2, 18%), and the left atrial appendage (n=1, 9%).

Conclusions

In comparison with published data on radio-frequency ablation, the dual-energy lattice-tip catheter appears to be associated with a higher rate of intra-procedural AF termination. Whether this increased termination rate translates into improved long-term outcomes, beyond the trend toward fewer in-hospital recurrences observed, remains to be determined. The inferior portion of the posterior wall emerged as a particularly frequent site of arrhythmia termination and may represent a relevant substrate for persistent AF.Table_1Table_2