The impact of catheter ablation on the dynamic function of the left atrium in patients with atrial fibrillation: insights from four-dimensional computed tomographic images.
BACKGROUND
Elucidating the functional properties and remodeling process of the entire left atrium (LA) is important not only for offering the mechanistic insight into atrial fibrillation (AF) but also for assessing the effectiveness of catheter ablation.


METHODS
We included 65 patients with paroxysmal AF and 29 controls. Baseline multidetector computed tomography (MDCT) was acquired in all subjects and a follow-up MDCT was available in 48 patients after pulmonary vein and LA ablation. The 3-dimensional images at atrial end-diastole (ED) and end-systole (ES) were analyzed.


RESULTS
The LA volume (ED: 61.11 +/- 15.94 vs 54.12 +/- 8.94 mL/m(2), P = 0.03; ES: 45.29 +/- 17.64 vs 33.38 +/- 7.78 mL/m(2), P < 0.001) was increased, and ejection fraction (EF) (26.93 +/- 13.40 vs 38.09 +/- 11.62%, P < 0.001) decreased in AF patients as compared to controls. After ablation, the ES LA volume (44.73 +/- 14.93 vs 38.04 +/- 11.51 mL/m(2), P = 0.04) decreased and the LA EF (25.04 +/- 13.13 vs 30.82 +/- 7.85%, P = 0.03) increased in patients without any AF recurrence. The wall motion (WM) analysis of the 18 segments of LA revealed increased motional magnitudes of entire LA except for the anterior roof. In contrast, the volume, EF, and WM of LA remained similar in patients with recurrence.


CONCLUSIONS
Dilated LA with global hypokinesia was noted in AF patients. Improved LA transport function was demonstrated in patients without any recurrence after ablation. However, the anatomic and functional reverse remodeling was not significant in patients with AF recurrence.
Tsao
Hsuan-Ming
HM
Division of Cardiology, National Yang-Ming University Hospital, I-Lan, Taiwan. hmtsao.pohai@msa.hinet.net
Hu
Wei-Chih
WC
Wu
Mei-Han
MH
Tai
Ching-Tai
CT
Chang
Shih-Lin
SL
Lin
Yenn-Jiang
YJ
Lo
Li-Wei
LW
Huang
Chin-Chou
CC
Hu
Yu-Feng
YF
Sheu
Ming-Huei
MH
Chang
Cheng-Yen
CY
Chen
Shih-Ann
SA
D001281:Atrial Fibrillation / Q000000981:diagnostic imaging* / Q000601:surgery*; D005260:Female; D006325:Heart Atria / Q000000981:diagnostic imaging* / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome