Introduction
The central importance of electrical pulmonary vein isolation (PVI) towards eliminating atrial fibrillation (AF) is well-established.1,2 Important progress towards improving procedural success was recently reported using site-specific contact force (CF) radiofrequency (RF) energy delivery targets, defined using a weighted formula incorporating RF power, CF and duration (Ablation Index, AI, Biosense Webster Inc., Diamond Bar, CA).3,4 This entire experimental approach was underpinned by a process of automated RF annotation (VISITAG™ Module, Biosense Webster), targeting a minimum inter-tag distance (ITD) of 6mm. However, this may represent an imperfect description of a genuinely reproducible PVI protocol, since – employing either conscious sedation or general anaesthesia (GA) with intermittent positive pressure ventilation (IPPV) – these studies5 routinely applied end-expiratory respiratory motion adjustment (RMA) to automated RF annotation settings (i.e. ACCURESP™ “on”). Importantly, such RMA use remains without in vivo validation. Therefore, in view of the importance of accurate RF auto-annotation at the LAPW due to the site-specific risk of atrio-oesophageal fistula (AEF), we retrospectively investigated the effects of RMA use on LAPW automated RF annotation, following CF-guided PVI.