The Effect Of Modified Box Lesion Via The Left Chest For Atrial Fibrillation Patients With Lad Less Than 45 Mm
Ju Mei, Zhaolei Jiang, Nan Ma, Hao Liu, Min Tang, Yi Si.
Xinhua Hospital, School of Medicine, Shanghai Jiaotong University School of Medicine, Shanghai, China.
OBJECTIVE: Entirely left atrium (LA) posterior wall isolation (PWI) may improve the outcomes of treating AF. We have performed epicardial circumferential left atrial ablation (CLAA) in addition to bilateral circumferential pulmonary vein isolation (CPVI) via left chest to reduce AF recurrence. However, we found that these two ablation lines of CLAA and left CPVI are very close in patients with left atrium diameter (LAD) less than 45 mm. The aim of this study was to evaluate the effect of modified Box lesion (CLAA and only right CPVI, Figure1) via left chest for AF patients with LAD less than 45 mm.
METHODS: From July 2013 to June 2016, we performed complete thoracic ablation of the left atrium via left chest for 112 AF patients (45 female) with LAD less than 45 mm. 47 cases had paroxysmal AF, 65 cases had persistent AF. Average patients' age was 60.8 ± 8.9 years. Average LAD was 41.2 ± 2.4 mm (range 35 - 45 mm). CLAA and only right CPVI (modified Box lesion group) were performed in 38 patients. CLAA and bilateral CPVI (CLAA+BCPVI group) were performed in 74 patients. Additional linear ablations were performed in both groups.
RESULTS: The CLAA+BCPVI group required longer ablation time (30.4±3.0mins vs. 24.6±2.5mins, P<0.001) than the modified Box lesion group. Procedure-related complication rates were not significantly different between the two groups (P>0.05). Five patients (4.1% vs 5.3%, P>0.05) had early AF recurrence after the ablation procedure. Cardioversion was performed on them before discharge. At discharge, maintenance of normal sinus rhythm was 100% in both groups. The mean follow-up duration was 22.4±10.1 months. Cumulative maintenance of normal sinus rhythm off antiarrhythmic drugs at 1 years postoperatively was 91.5±3.3% in CLAA+BCPVI group and 90.6±5.2% in modified Box lesion group (P=0.982).
CONCLUSIONS: Compared with CLAA+BCPVI, modified Box lesion could achieve the similar sinus rhythm maintenance rates for AF patients with LAD less than 45 mm, but simplify the ablation procedure and reduce the ablation time.
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