Interatrial septal thickness is associated with the extent of left atrial complex fractionated atrial electrograms and acute procedural outcome in patients with persistent atrial fibrillation.
OBJECTIVE
The interatrial septal thickness (IAST) reflects the changes of the atrial wall in patients with atrial fibrillation (AF). Complex fractionated atrial electrograms (CFAEs) were consistently positioned on the interatrial septum, especially in the remodelled left atrium (LA). We sought to characterize the relationship between IAST and LA CFAE area, as well as the acute procedural and clinical outcomes of catheter ablation in persistent AF patients.


RESULTS
This study included 71 patients who underwent catheter ablation for drug-refractory persistent AF. A stepwise ablation approach included circumferential pulmonary vein isolation followed by LA and right atrial CFAE-guided ablation. Interatrial septal thickness was measured 1 cm inferior to the fossa ovalis on cardiac computed tomography (CT). The extent of LA CFAEs was assessed by CFAE area and index (CFAE area/LA surface area × 100). Patients were grouped into tertiles according to the value of IAST. The mean IAST of the first, second, and third tertile was 4.69 ± 0.79, 6.44 ± 0.45, and 9.12 ± 1.42 mm, respectively (P < 0.001). The mean CFAE areas (5.6 ± 6.9, 18.5 ± 20.3, and 24.3 ± 26.6 mm(2), P = 0.005) and CFAE indexes (3.1 ± 4.2, 9.2 ± 10.7, and 11.8 ± 15.3, P = 0.025) in LA were significantly different among the three groups. More patients in the highest IAST tertile did not terminate AF during catheter ablation (12.5% vs. 26.1% vs. 37.5%, P = 0.048).


CONCLUSIONS
Interatrial septal thickness measured by cardiac CT is associated with the extent of CFAE area within the LA and is related to acute procedural success of catheter ablation. These findings suggest that IAST reflects the degree of atrial substrate and remodelling in patients with persistent AF.
Division of Cardiology, Anam Hospital, Korea University Medical Center, Korea University, 126-1 Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, South Korea.
Yae Min
YM
Park
Division of Cardiology, Anam Hospital, Korea University Medical Center, Korea University, 126-1 Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, South Korea.
Hwan Cheol
HC
Park
Division of Cardiology, Anam Hospital, Korea University Medical Center, Korea University, 126-1 Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, South Korea.
Ji-Eun
JE
Ban
Division of Cardiology, Anam Hospital, Korea University Medical Center, Korea University, 126-1 Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, South Korea.
Jong-Il
JI
Choi
Division of Cardiology, Anam Hospital, Korea University Medical Center, Korea University, 126-1 Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, South Korea.
Hong Euy
HE
Lim
Division of Cardiology, Anam Hospital, Korea University Medical Center, Korea University, 126-1 Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, South Korea.
Sang Weon
SW
Park
Division of Cardiology, Anam Hospital, Korea University Medical Center, Korea University, 126-1 Anam-Dong 5Ga, Seongbuk-Gu, Seoul 136-705, South Korea yhkmd@unitel.co.kr.
Young-Hoon
YH
Kim
D000200:Action Potentials; D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016279:Atrial Function, Left; D064752:Atrial Remodeling; D054087:Atrial Septum / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D016896:Treatment Outcome
Atrial fibrillation; Complex fractionated atrial electrograms; Interatrial septal thickness