Spatiotemporal organization of the left atrial substrate after circumferential pulmonary vein isolation of atrial fibrillation.
BACKGROUND
There is a paucity of data regarding the mechanism of maintaining atrial fibrillation (AF) after pulmonary vein isolation (PVI) in patients with AF. The aim of this study was to examine the impact of circumferential PVI on the left atrial (LA) substrate characteristics.


RESULTS
Seventy-two AF patients (age, 53+/-11 years) underwent mapping and catheter ablation using an NavX system. The biatrial characteristics such as the complex fractionated atrial electrograms (CFEs; based on fractionated intervals) and frequency analysis (based on dominant frequencies) were mapped before and after PVI. PVI with electric isolation was performed in all patients. In the 45 patients who did not respond to PVI, the continuous CFEs (>8 seconds, 18+/-18% and 12+/-17% of the LA sites, before and after PVI, respectively, P=0.02), degree of LA fractionation (mean fractionated interval: 75.6+/-14.3 msec versus 87.3+/-16.7 msec, P=0.001), and mean LA dominant frequencies (6.92+/-0.88 Hz versus 6.58+/-0.91 Hz, P=0.001) decreased after PVI. Complete PVI altered the distribution of the CFEs toward the LA anteroseptum, mitral annulus, and LA appendage regions. A persistent presence of continuous CFEs in the vicinity of the dominant frequencies sites (observed in 53% patients) correlated with a higher procedural AF termination rate for the CFE ablation (63% versus 23%, P<0.05).


CONCLUSIONS
Complete PVI eliminated some CFEs in the LA and altered the distribution of the CFEs. The persistent presence of CFEs before and after PVI in the vicinity of the high frequency sites is important for AF maintenance after PVI.
Lin
Yenn-Jiang
YJ
Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
Tai
Ching-Tai
CT
Kao
Tsair
T
Chang
Shih-Lin
SL
Lo
Li-Wei
LW
Tuan
Ta-Chuan
TC
Udyavar
Ameya R
AR
Wongcharoen
Wanwarang
W
Hu
Yu-Feng
YF
Tso
Han-Wen
HW
Tsai
Wen-Chin
WC
Chang
Chien-Jung
CJ
Ueng
Kuo-Chang
KC
Higa
Satoshi
S
Chen
Shih-Ann
SA
D000328:Adult; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery*; D016279:Atrial Function, Left; D017115:Catheter Ablation / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D011651:Pulmonary Artery / Q000601:surgery*; D016896:Treatment Outcome