Morphological changes of the left atrial appendage after catheter ablation of atrial fibrillation.
BACKGROUND
The left atrial appendage (LAA) has been proven to be the most important site of thrombus formation in patients with atrial fibrillation (AF). However, the information regarding the morphometric alteration of the LAA related to the outcome of AF ablation is still lacking. Thus, we evaluated the long-term changes of the LAA morphology in patients undergoing catheter ablation of AF using magnetic resonance angiography (MRA).


RESULTS
Group 1 included 15 controls without any AF history. Group 2 included 40 patients with drug-refractory paroxysmal AF. They were divided into two subgroups: group 2a included 30 patients without AF recurrence after pulmonary vein (PV) ablation. Group 2b included 10 patients with late recurrence of AF. The LAA morphology before and after (20 +/- 11 months) ablation was evaluated by three-dimensional MRA. The group 2 patients had a larger baseline LAA size (including the LAA orifice, neck, and length) and less eccentric LAA orifice and neck. After the AF ablation, there was a significant reduction in the LAA size in the group 2a patients, and the morphology of the LAA neck became more eccentric during the follow-up period. In group 2b, the LAA size increased and no significant change in the eccentricity of the orifice and neck could be noted.


CONCLUSIONS
The morphometric remodeling of the LAA in the AF patients could be reversed after a successful ablation of the AF. Progressive dilation of the LAA was noted in the patients with AF recurrence. These structural changes in the LAA may play a role in reducing the potential risk of cerebrovascular accidents.
Chang
Sheng-Hsiung
SH
Division of Cardiovascular Medicine, Mackay Memorial Hospital, Taipei, Taiwan.
Tsao
Hsuan-Ming
HM
Wu
Mei-Han
MH
Tai
Ching-Tai
CT
Chang
Shih-Lin
SL
Wongcharoen
Wanwarang
W
Lin
Yenn-Jiang
YJ
Lo
Li-Wei
LW
Hsieh
Ming-Hsiung
MH
Sheu
Ming-Huei
MH
Chang
Cheng-Yen
CY
Hou
Charles Jia-Yin
CJ
Chen
Shih-Ann
SA
D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D006328:Cardiac Catheterization; D017115:Catheter Ablation; D017548:Echocardiography, Transesophageal; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period