Efficacy of linear block at the left atrial roof in atrial fibrillation

Background: After extensive encircling of ipsilateral pulmonary vein isolation (EEPVI) for atrial fibrillation (AF), we sometimes observe AF recurrence, or the occurrence of atrial tachycardia originating from the left atrium. This study examined the efficacy of additional linear ablation at the left atrial (LA) roof in combination with EEPVI to prevent arrhythmia recurrences.

Methods: This study included 104 patients with drug-refractory AF (75 with paroxysmal, 29 with persistent). The patients in Group A (n=70) underwent EEPVI treatment alone, and the patients in Group B (n=34) underwent linear ablation at the LA roof in addition to EEPVI treatment. At 1, 3, 6, and 12 months after ablation, patients underwent clinical review and 24-h ambulatory electrocardiogram monitoring to identify asymptomatic arrhythmias. Follow-up included daily trans-telephonic event monitoring, transmitted irrespective of the patient's symptoms.

Results: At 12 months, 57% of Group A and 79% of Group B were free of arrhythmias (p<0.05). Cox regression analysis demonstrated that among the variables of age, sex, duration of AF, types of AF (paroxysmal or persistent), LA size, ejection fraction, existence of hypertension, ischemic heart disease, valvular heart disease, history of stroke, and the ablation technique, only the ablation technique of the linear block at the LA roof was the independent predictor of arrhythmia-free recovery after ablation.

Conclusions: EEPVI in combination with the linear ablation at the LA roof is associated with an improved clinical outcome compared with EEPVI alone.