Atrial tachycardias: Cause or effect with ablation of persistent atrial fibrillation?. (22nd November 2017) - Yamashita, Seigo
Abstract: Introduction: It is largely believed that atrial tachycardias (ATs) encountered during ablation of persistent atrial fibrillation (PsAF) are a byproduct of ablative lesions. We aimed to explore the alternative hypothesis that they may be a priori drivers of AF remaining masked until other AF sources are reduced or eliminated. Methods and results: Radiofrequency ablation of fibrillatory drivers mapped by electrocardiographic imaging (ECGI; ECVUE™, Cardioinsight Technologies, Cleveland, OH, USA) terminated PsAF in 198 (73%) out of 270 patients (61 ± 10 years, 9 ± 9 m). Two hundred and six ATs in 158 patients were subsequently mapped. Their anatomic relationship to the fibrillatory drivers prospectively identified by ECGI was then established. There were 26 (13%), 52 (25%), and 128 (62%) focal, localized, and macrore‐entrant ATs, respectively. In focal/localized re‐entrant ATs, 64 (82%) were terminated within an AF‐driver region, in which 26 (81%) among 32 focal/localized ATs analyzed with 3‐D‐mapping system merged to driver map occurred from AF‐driver regions in 1.0 ± 1.0 cm distance from the driver core. Importantly, there was no attempt at ablation of the associated AF‐driver region in 25 of 64 (39%) of focal/localized re‐entrant ATs. The sites of ATs origin generally had low‐voltage, fractionated, and long‐duration electrograms in AF. All but two focal/localized re‐entrant ATs were successfully ablated. Conclusion: The majority of post‐AF‐ablation focal and localized re‐entrant ATs originate from the region of prospectively established AF‐driver regions. A third of these are localized to regions not subsequently submitted to ablation. These data suggest that many ATs exist, although not necessarily manifest independently, prior to ablation. They may have a role in the maintenance of PsAF in these individuals.