The impact of left atrial size on long-term outcome of catheter ablation of chronic atrial fibrillation.
BACKGROUND
The left atrial (LA) size is an important predictor of atrial fibrillation (AF) procedural termination and the long-term outcome. We sought to evaluate the long-term outcome in regard to the LA size and procedural termination.


METHODS
Eighty-seven consecutive chronic AF patients (72 males, 53 +/- 10 years) underwent 3D mapping (NavX) and ablation. A stepwise approach including circumferential pulmonary vein (PV) isolation, linear ablation, and continuous complex-fractionated electrogram (CFE) ablation (targeting fractionation intervals of < 50 ms). Electrical cardioversion was applied to those without any procedural termination. The freedom from AF was defined as the maintenance of sinus rhythm without the use of any class I or III antiarrhythmic drugs after the blanking period.


RESULTS
Among the 87 patients, all received a circumferential PV isolation, 93% a linear ablation, and 59% a continuous CFE ablation. Those with AF procedural termination (n = 30) had a better long-term outcome when compared with those without termination during a follow-up of 21 +/- 12 months. Moreover, a Kaplan-Meier analysis showed that in those with an LA diameter of less than 45 mm (n = 49), the freedom from AF rate was higher when procedural termination was achieved (P = 0.004). On the contrary, the outcome was comparable in those with an LA diameter of >or= 45 mm (n = 38), whether AF procedural termination occurred or not (P = 0.658).


CONCLUSIONS
AF procedural termination was related to the long-term success during chronic AF ablation, especially in those with an LA diameter of less than 45 mm. The favorable effect of termination decreased when the LA diameter was >or= 45 mm.
Lo
Li-Wei
LW
Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
Lin
Yenn-Jiang
YJ
Tsao
Hsuan-Ming
HM
Chang
Shih-Lin
SL
Udyavar
Ameya R
AR
Hu
Yu-Feng
YF
Ueng
Kwo-Chang
KC
Tsai
Wen-Chin
WC
Tuan
Ta-Chun
TC
Chang
Chien-Jung
CJ
Tang
Wei-Hua
WH
Higa
Satoshi
S
Tai
Ching-Tai
CT
Chen
Shih-Ann
SA
D001281:Atrial Fibrillation / Q000473:pathology* / Q000601:surgery*; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation / Q000379:methods*; D002908:Chronic Disease; D005260:Female; D006325:Heart Atria / Q000473:pathology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011379:Prognosis; D016896:Treatment Outcome