Abstract

Atrial tachycardias after catheter ablation of atrial fibrillation are a significant complication as these arrhythmias are often more symptomatic than index arrhythmia and require a repeat ablation procedure for long-term maintenance of sinus rhythm. The reported incidence ranges from <5% to 50% with an increased risk when atrial fibrillation duration is prolonged and when extensive lesions are performed, in addition to pulmonary vein isolation, during the index ablation procedure. Macro-reentry is the most common mechanism while localized reentry represents the majority of focal atrial tachycardias. Electroanatomical mapping using a stepwise approach is the cornerstone for evaluation of the underlying mechanism and ablation guidance. For focal tachycardias, ablation targets the site of earliest activation that usually involves a reconnected pulmonary vein ostium. In localized reentry, localization is based on identification of electrogram fractionation covering a great proportion of the cycle length within a small area while linear ablation is the approach of choice for the most frequent macro-reentrant atrial tachycardias.

Keywords: Atrial tachycardia; Catheter ablation; Macro-reentry; Localized reentry; Atrial fibrillation ablation