Left atrial linear lesions are required for successful treatment of persistent atrial fibrillation. Commentary

Aims This study evaluates the clinical outcome and incidence of left atrial (LA) macro re-entrant atrial tachycardia (AT) in patients in whom persistent atrial fibrillation (AF) terminated during catheter ablation without the need of roof and mitral lines. Methods Persistent AF was terminated by ablation in 154 of 180 consecutive patients. AF history was 60 months including 11 and results months of continuous AF. Patients were divided into two groups: those who had not required both LA linear lesions to terminate AF (group A, 85 patients), and those who had (group B, 69 patients). There was no difference in clinical and echocardiographic characteristics between both groups except for a shorter duration of continuous AF in group A (9 vs.12 months, respectively) (P = 0.03). After 28 months of follow-up, the incidence of LA macro re-entrant AT necessitating linear ablation was higher in group A (76%) compared with group B (33%) (P = 0.002). When complete linear block could not be achieved during the index procedure, the incidence of subsequent roof (P = 0.008) or mitral isthmus (P = 0.010) dependent macro re-entrant AT was higher. Conclusion Although persistent AF can be terminated by catheter ablation without linear lesions, the majority will require linear lesions for macro re-entrant AT.