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Tomlinson, D. R.

Publications and source records attributed to Tomlinson, D. R..

3 recordsLinked to original sources
bioRxiv2019

Ablation catheter motion detection during contact force and VISITAG™ Module-guided pulmonary vein isolation

BackgroundDuring contact force (CF) and VISITAG Module (Biosense Webster) guided pulmonary vein isolation (PVI), ACCURESP respiratory motion adjustment is recommended, although without in vivo validation.\n\nObjectiveSince 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).\n\nMethodsFrom 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.\n\nResultsThere 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) 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\".\n\nConclusionsACCURESP \"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.

physiology↗
bioRxiv2018

Assessment of the transmural unipolar electrogram morphology change radius during contact force-guided pulmonary vein isolation using the VISITAG&trade; Module and CARTOREPLAY&trade;

AimsTo investigate the radius of transmural (TM) ablation effect at the left atrial posterior wall (LAPW) during contact force (CF)-guided pulmonary vein isolation (PVI), using pure R unipolar electrogram (UE) morphology change - a histologically validated marker of radiofrequency (RF)-induced TM atrial ablation.\n\nMethodsFollowing PVI in 24 consecutive patients (30W, continuous RF), VISITAG Module and CARTOREPLAY (Biosense Webster Inc.) RF and UE data at left and right-sided LAPW annotated sites 1 and 2 were analysed.\n\nResultsAcutely durable PVI without spontaneous / dormant recovery was achieved following 15s and 10-11s RF, at sites 1 and 2, respectively (p<0.0001). At site 1, RS UE morphology was noted pre-ablation, with RF-induced pure R UE morphology change in 47/48 (98%). Left and right-sided second RF site annotation was at 5.8mm and 5.2mm from site 1 respectively (p=0.64), yet immediate pure R UE morphology was noted in 35/48 (73%). For second-annotated sites, 30 demonstrated inter-ablation site transition time [&le;]17ms; pure R UE morphology was noted at annotation onset in 22/30 (73%), with overall median time to pure R morphology change significantly shorter than at site 1 - 0.0s, versus 4.1s and 5.3s, for left and right-sided first-annotated LAPW sites, respectively (p<0.0001).\n\nConclusionWhen the first and second-annotated LAPW RF sites were within 7mm, 73% second-annotated sites demonstrated immediate pure R UE morphology change. These analyses support a paradigm of shorter RF duration at immediately adjacent sites during continuous RF application, and may usefully inform the further development of \"tailored\" approaches towards CF-guided PVI.\n\nWhats known?O_LIThe VISITAG Module and CARTOREPLAY permit investigations into the tissue effects of RF energy delivery in vivo, via objective annotation methodology and retrospective evaluation of histologically validated unipolar electrogram (UE) criteria for transmural (TM) atrial ablation.\nC_LIO_LIGreater RF energy effect is seen at left compared to right-sided first-annotated left atrial posterior wall (LAPW) sites during pulmonary vein isolation (PVI).\nC_LI\n\nWhats new?O_LIFollowing [~]15s RF delivery at first-annotated LAPW sites and aiming for [&le;]6mm inter-ablation site distance during continuous RF delivery, 73% second-annotated sites demonstrated immediate TM UE morphology change.\nC_LIO_LIAt second-annotated sites, [~]10s RF resulted in acutely durable PVI in all. Greater left-sided RF energy effect was observed, not explained by differences in RF duration, mean CF or catheter position stability.\nC_LIO_LIThe radius of TM RF effect may be determined at the LAPW following CF and VISITAG Module-guided PVI.\nC_LI

physiology↗
bioRxiv2017

Derivation and validation of a VISITAG&trade;-guided contact force ablation protocol for pulmonary vein isolation

Aims Following radiofrequency (RF) pulmonary vein isolation (PVI), atrial fibrillation (AF) recurrence mediated by recovery of pulmonary vein (PV) conduction is common. I examined whether comparative VISITAG (Biosense Webster Inc.) data analysis at sites showing intra-procedural recovery of PV conduction versus acutely durable ablation could inform the derivation of a more effective VISITAG-guided contact force (CF) PVI protocol.\n\nMethods and results Retrospective analysis of VISITAG Module annotated ablation site data in 10 consecutive patients undergoing CF-guided PVI without active VISITAG guidance. Employing 2mm positional stability range and lenient CF filter (force-over-time 10%, minimum 2g), inter-ablation site distance >10-12mm, adjacent 0g-minimum CF and short RF duration (3-5s) were associated with intra-procedural recovery of PV conduction. A VISITAG-guided CF PVI protocol was derived employing [&le;]6mm inter-ablation site distances, minimum target ablation site duration [&ge;]9s / force time integral (FTI) 100gs and 100% 1g-minimum CF filter. Seventy-two consecutive VISITAG-guided CF PVI procedures were then undertaken using this protocol, with PVI achieved in all utilising 23.8[8.4] minutes total RF (30W, 48{degrees}C, 17ml/min, continuous RF application). Following protocol completion, acute intra-procedural spontaneous / dormant recovery of PV conduction requiring touch-up RF occurred in 1.4% / 1.8% of PVs, respectively. At 14[5] months follow-up in all 34 patients with paroxysmal AF [&ge;]6 months post-ablation, 30 (88%) were free from atrial arrhythmia, off class I/III anti-arrhythmic medication.\n\nConclusion VISITAG provides means to identify and then avoid factors associated with intra-procedural recovery of PV conduction. This VISITAG Module-guided CF PVI protocol demonstrated excellent intra-procedural and long-term efficacy.\n\nCondensed abstract Following CF-guided PVI, retrospective VISITAG Module analyses permitted the identification of ablation parameters associated with intra-procedural recovery of PV conduction. The derived VISITAG Module-guided CF PVI protocol employed short over RF duration yet proved efficient at achieving PVI acutely, with long-term follow-up demonstrating high clinical efficacy.

physiology↗