Cor Vasa 2004, 45(3):103-109

Catheter radiofrequency ablation of atrial fibrillation performed with the support of electroanatomical mapping

Petr Neužil^1,*, Vivek Reddy², Miloš Táborský¹, Lucie Šedivá¹, Roman Vopálka¹, Jan Petrů¹, Dan Gross¹, Štěpán Královec¹, Petr Niederle¹

¹ Kardiologické oddělení, Nemocnice Na Homolce, Praha, Česká republika

² Cardiac Arrhythmia Services of Massachusetts General Hospital, Boston, USA

Aim of study:
In recent years, the role of catheter ablation as a curative procedure in the treatment of atrial fibrillation (AF) has become increasingly important. Our study was designed to assess our initial experience with performing radiofrequency ablation (RFA) in patients with various forms of atrial AS (paroxysmal, persistent, permanent).

Method:
A total of 35 catheter ablation procedures for AF were performed in our department over the years 2001-2002. All procedures were undertaken using electroanatomical mapping with a CARTO system, and with the help of activation or voltage left atrial mapping. A circular catheter for electrical potential mapping in the pulmonary vein ostial region was inserted via a second transseptal puncture in about a half of patients. The purpose of the procedure was to achieve complete electrical isolation of the pulmonary veins. Linear radiofrequency lesions were performed using a periostially flushed catheter. Repeat mapping of the isolated area of the intervened pulmonary vein was undertaken either in sinus rhythm within the isolated zone, or during pacing via the circular catheter inserted outside the zone.

Results:
Overall, 35 linear RFA procedures in the left atria of 34 patients were performed. Mean procedure duration was 4.7 ± 1.2 (3-9.5) hours with fluoroscopy times of 46.1 ± 17.4 (18.5-67) minutes. Complete electrical isolation of all detected pulmonary veins was achieved in 19 patients. In 16 patients, evidence of achieving complete electrical isolation, in addition to subsequent re-mapping of the ablation line with the CARTO system, was obtained using the circular catheter. Partial isolation (always in the region of the left or right pulmonary vein ostia) was documented at the end of the procedure in another seven patients. Electrical isolation was not accomplished in 8 patients. The procedure was complemented with cavotricuspid isthmus ablation line in all patients. At 10.7 ± 2.6 months of follow-up, AF recurrence was documented in 7 patients (20%), atrial flutter recurred in 2 patients (while noted in a total of 7 patients prior to the ablation procedure). We did not demonstrate a significant difference in AF recurrence rates in patients with pulmonary vein electrical isolation documented using the circular catheter (n = 16) or CARTO system re-mapping (n = 19).
No major ablation-related complication was seen besides pericardial effusion in one case, which was the reason for pericardial draining.

Conclusion:
Our data clearly show catheter ablation of AF is today a safe yet still relatively effective method for managing this arrhythmia (20% recurrence rates within one-year follow-up). Application of catheter ablation with chronic forms of AF depends on improving our knowledge of the pathophysiology and exact mechanism of AF propagation as well as rapid development of new technology.

Keywords: Catheter radiofrequency ablation; Atrial fibrillation; Electroanatomical mapping

Published: March 1, 2004  Show citation