Does Additional Linear Ablation After Circumferential Pulmonary Vein Isolation Improve Clinical Outcome in Patients With Paroxysmal Atrial Fibrillation? Prospective Randomised Study
Are ablation lines of clinical value in patients with paroxysmal atrial fibrillation (PAF) who have undergone pulmonary vein isolation (PVI) by radiofrequency catheter ablation (RFCA)?
One hundred fifty-six patients (mean age 56 years) with PAF were randomly assigned to undergo circumferential PVI (n = 52), PVI plus a roof line (PVI + RL, n = 52), or PVI plus a roof and a posterior-inferior left atrial line (PVI + Box, n = 52). Holter monitoring was performed at 3, 6, and 12 months of follow-up. The mean duration of follow-up was 16 months.
The total procedure time was approximately 10-20 minutes longer in the PVI + RL and PVI + Box groups than in the PVI group. There were no significant differences in the rate of recurrent PAF after the first 3 months of follow-up in the absence of antiarrhythmic drug therapy between the PVI group (9.6%), the PVI + RL group (17.3%), and the PVI + Box group (13.5%).
The authors concluded that linear ablation does not improve efficacy in patients with PAF undergoing PVI by RFCA.
PAF typically is triggered by ectopy arising in the muscle sleeves surrounding the PVs and sometimes other thoracic veins. This explains why PVI most often is sufficient to eliminate PAF. When PAF recurs after PVI, this usually is attributable to resumption of PV conduction. Linear ablation modifies the AF substrate, but does not eliminate the AF triggers. Therefore, linear ablation would not be expected to improve the efficacy of PVI for PAF. Although not demonstrated in this study, another reason to avoid linear ablation is that it can result in new atrial tachycardias.
Keywords: Tachycardia, Supraventricular, Heart Atria, Follow-Up Studies, Lactation, Pulmonary Veins, Electrocardiography, Ambulatory, Heart Rate, Catheter Ablation, Dairying
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