Word count:Abstract 250; body text 4371; references 771 2 Abstract Background During contact force (CF) and VISITAG™ Module (Biosense Webster) guided pulmonary vein isolation (PVI), ACCURESP™ respiratory motion adjustment is recommended, although without in vivo validation. ObjectiveSince accurate LAPW radiofrequency (RF) annotation is crucial to avoid oesophageal thermal injury, we compared ACCURESP™ setting ("on" versus "off") on RF annotation at the left atrial posterior wall (LAPW). MethodsFrom a twenty-five patient cohort undergoing CF PVI (continuous RF, 30W) using general anaesthesia and VISITAG™ Module annotation-guidance (force-over-time 100% minimum 1g, 2mm position stability, ACCURESP™ "off"), respiratory motion detection occurred in eight, permitting retrospective comparison of ACCURESP™ settings. ResultsThere were significant differences in LAPW RF data annotation according to ACCURESP™ setting. Comparing ACCURESP™ "on" versus "off", respectively: Total annotated sites 82 versus 98; Median RF duration per-site 13.3s versus 10.6s (p<0.0001); Median force time integral 177g.s versus 130g.s (p=0.0002); Mean inter-lesion distance (ILD) 6.0mm versus 4.8mm (p=0.002). Considering only annotated site 1-to-2 transitions, three occurred with 0g CF; ACCURESP™ "on" minus "off" difference in RF duration was <0.6s. However, thirteen site 1-to-2 transitions during constant catheter-tissue contact (ILD range 2.1 -7.0mm) 3 demonstrated a mean difference in annotated RF duration at site 1, of 3.7s (Range: -1.3 -11.3s). Reconstituted curves displaying catheter position data, CF, impedance and site 1-to-2 transition according to ACCURESP™ setting, demonstrated multiple markers of catheter movement coinciding with ACCURESP™ "off". ConclusionsACCURESP™ "off" setting demonstrated excellent catheter movement detection properties and represents an optimal method towards the annotation of stable sites of RF delivery at the LAPW. 4 KeywordsAtrial fibrillation; contact force catheter ablation; pulmonary vein isolation; ACCURESP™ Module; VISITAG™ Module

Background During automated radiofrequency (RF) annotation‐guided pulmonary vein isolation (PVI), respiratory motion adjustment (RMA) is recommended, yet lacks in vivo validation. Methods Following contact force (CF) PVI (continuous RF, 30 W) using general anesthesia and automated RF annotation‐guidance (VISITAG™: force‐over‐time 100% minimum 1 g; 2 mm position stability; ACCURESP™ RMA “off”) in 25 patients, we retrospectively examined RMA settings “on” versus “off” at the left atrial posterior wall (LAPW). Results Respiratory motion detection occurred in eight, permitting offline retrospective comparison of RMA settings. Significant differences in LAPW RF auto‐annotation occurred according to RMA setting, with curves displaying catheter position, CF and impedance data indicating “best‐fit” for catheter motion detection using RMA “off.” Comparing RMA “on” versus “off,” respectively: total annotated sites, 82 versus 98; median RF duration per‐site, 13.3 versus 10.6 s (p < 0.0001); median force time integral 177 versus 130 gs (p = 0.0002); mean inter‐tag distance (ITD), 6.0 versus 4.8 mm (p = 0.002). Considering LAPW annotated site 1‐to‐2 transitions resulting from deliberate catheter movement, 3 concurrent with inadvertent 0 g CF demonstrated < 0.6 s difference in RF duration. However, 13 deliberate catheter movements during constant tissue contact (ITD range: 2.1–7.0 mm) demonstrated (mean) site‐1 RF duration difference 3.7 s (range: −1.3 to 11.3 s): considering multiple measures of catheter position instability, the appropriate indication of deliberate catheter motion occurred with RMA “off” in all. Conclusions ACCURESP™ respiratory motion adjustment importantly delayed the identification of deliberate and clinically relevant catheter motion during LAPW RF delivery, rendering auto‐annotated RF display invalid. Operators seeking greater accuracy during auto‐annotated RF delivery should avoid RMA use.

Background During automated radiofrequency (RF) annotation-guided pulmonary vein isolation (PVI), respiratory motion adjustment (RMA) is recommended, yet lacks in vivo validation. Methods Following contact force (CF) PVI (continuous RF, 30W) using general anaesthesia and automated RF annotation-guidance (VISITAG™: force-over-time 100% minimum 1g; 2mm position stability; ACCURESP™ RMA “off”) in 25 patients, we retrospectively examined RMA settings “on” versus “off” at the left atrial posterior wall (LAPW). Results Respiratory motion detection occurred in 8, permitting offline retrospective comparison of RMA settings. Significant differences in LAPW RF auto-annotation occurred according to RMA setting, with curves displaying catheter position, CF and impedance data indicating “best-fit” for catheter motion detection using RMA “off”. Comparing RMA “on” versus “off”, respectively: Total annotated sites 82 versus 98; median RF duration per-site 13.3s versus 10.6s (p<0.0001); median force time integral 177g.s versus 130g.s (p=0.0002); mean inter-tag distance (ITD) 6.0mm versus 4.8mm (p=0.002). Considering LAPW annotated site 1-to-2 transitions resulting from deliberate catheter movement, 3 concurrent with inadvertent 0g CF demonstrated <0.6s difference in RF duration. However, 13 deliberate catheter movements during constant tissue contact (ITD range 2.1 – 7.0mm) demonstrated (mean) site-1 RF duration difference 3.7s (range: -1.3 to 11.3s): considering multiple measures of catheter position instability, the appropriate indication of deliberate catheter motion occurred with RMA “off” in all. Conclusions ACCURESP™ respiratory motion adjustment importantly delayed the identification of deliberate and clinically relevant catheter motion during LAPW RF delivery, rendering auto-annotated RF display invalid. Operators seeking greater accuracy during auto-annotated RF delivery should avoid RMA use.