A Method to Improve the Fidelity of Voltage Mapping to Guide Substrate-Based Atrial Fibrillation Ablation?
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See Article by Haldar et al
Catheter ablation is an increasingly used treatment option for patients with symptomatic atrial fibrillation (AF). Pulmonary vein isolation is the cornerstone of AF ablation and is the preferred ablation strategy in patients with paroxysmal AF, but the optimal ablation strategy in patients with persistent and long-standing persistent AF remains controversial. Randomized controlled trials have suggested limited ablation strategies targeting pulmonary vein isolation alone to be as effective in achieving freedom from recurrent atrial arrhythmias for patients with nonparoxysmal AF as strategies which involve more extensive ablation.1,2 However, it is well known that changes in both the electric and anatomic atrial substrate can occur in patients with nonparoxysmal AF, and the degree of atrial fibrosis has been demonstrated to strongly predict likelihood of success after AF ablation.3 As a result, many think that additional modification of the underlying substrate in certain patients may be required to improve long-term ablation outcomes. Nonrandomized studies examining different substrate-based ablation approaches have shown possible benefit in certain patient populations: recent examples of atrial substrate ablation which have been proposed include ablation of low-voltage areas (LVA), box isolation of fibrotic areas, and voltage-guided posterior wall isolation.4–8
In all of these substrate-based ablation strategies, identification of ablation targets seems to be reliant on the fidelity of the electroanatomic bipolar voltage maps. The accuracy of voltage maps when used to identify atrial substrate is dependent on the underlying rhythm. It is well known that bipolar voltages of atrial electrograms are lower when measured during AF as compared with sinus rhythm, and Yagishita et al9 have demonstrated that only a fair …