Successful radiofrequency ablation in patients with previous atrial fibrillation results in a significant decrease in left atrial size.

BACKGROUND: The objective of the present study was to evaluate the relation between freedom from atrial fibrillation (AF) and left atrial (LA) size in patients who underwent circumferential pulmonary vein (PV) isolation and LA ablation.

METHODS AND RESULTS: One hundred five consecutive patients with symptomatic and drug-refractory paroxysmal or persistent AF were included in the present study. The mean age was 52+/-9.5 years (range, 27 to 75 years); 74 patients (70%) were male. Paroxysmal AF was present in 52 (49.5%) and persistent AF in 53 (50.5%) patients. Mean AF duration was 6.0+/-5.1 years in the paroxysmal AF group and 7.6+/-6.0 years in the persistent AF group. A 3D electroanatomic map of the LA including the PV ostia was constructed with a nonfluoroscopic navigation system (Carto, Biosense Webster). Left- and right-sided PVs were encircled by continuous radiofrequency ablation lines. We performed 128 ablation procedures in 105 patients, ie, 23 redo procedures. The mean long-term follow-up duration was 14.6+/-4.9 months (range, 6 to 24 months). Sinus rhythm was present in 45 patients (86.5%) in the paroxysmal AF group and in 41 patients (77.3%) in the persistent AF group at the latest follow-up. Six months after ablation, LA dimension in the persistent AF subjects who remained in sinus rhythm decreased from 44.0+/-5.8 to 40+/-4.5 mm (range, 31 to 51 mm). In contrast, in patients with recurrences of AF, LA dimension increased from 45+/-6.5 to 49+/-5.4 mm (range, 32 to 59 mm). In the successfully treated paroxysmal AF group, LA dimension decreased from 40.5+/-4.4 to 37.5+/-3.5 mm (P<0.01).

CONCLUSIONS: In radiofrequency ablation of AF using an electroanatomic approach, there is a statistically significant relationship between medium-term procedural success and LA size: persistent sinus rhythm is associated with reduced and recurrent AF with increased LA dimensions.