INTRODUCTION
Pulmonary vein isolation (PVI) has been the cornerstone of atrial fibrillation (AF) ablation. However, the single procedure success rates are limited, particularly in persistent and longstanding persistent AF.1 However, additional strategies including linear ablation and ablation of complex fractionated atrial electrograms (CFAEs) 2,3 have not indicated any efficacy benefit over a PVI alone in non-paroxysmal AF patients. 4
A strategy based on low-voltage areas (LVAs) as detected by left atrial (LA) voltage mapping during sinus rhythm (SR) has recently been reported because LVAs are a predictor of AF recurrence after AF ablation.5,6,7 Furthermore, the recent utility of the Advisor HD grid HD (HDG) mapping catheter (Abbott Technologies, St Paul, Minnesota, USA) might lead to new and unique mapping techniques. The HDG contributes to the bipolar recording of activation parallel and perpendicular to the splines, which differs from conventional mapping.8 Therefore, the HDG can create high density maps to define anatomical substrates regardless of the direction of the activation.
High-DF sites may be potential selective targets for localized sources maintaining AF in non-paroxysmal AF patients.9,10,11However, high-DF areas change spatiotemporally and the DF based ablation is still controversial.12 Therefore, we previously reported the importance of high-DF sites overlapping with present LVAs using a conventional mapping catheter after the PVI.13 Recently, the areas in which rotational activations are frequently observed are automatically detected by a novel phase mapping system among some ablation strategies targeting AF drivers.14-16 This study aimed to evaluate the relationship between the DFs/rotors and LVAs detected using the HDG after PVI in non-paroxysmal AF.