scholarly journals The role of local impedance drop in the acute lesion efficacy during pulmonary vein isolation performed with a new contact force sensing catheter—A pilot study

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257050
Author(s):  
Nándor Szegedi ◽  
Zoltán Salló ◽  
Péter Perge ◽  
Katalin Piros ◽  
Vivien Klaudia Nagy ◽  
...  

Introduction Our pilot study aimed to evaluate the role of local impedance drop in lesion formation during pulmonary vein isolation with a novel contact force sensing ablation catheter that records local impedance as well and to find a local impedance cut-off value that predicts successful lesion formation. Materials and methods After completing point-by-point radiofrequency pulmonary vein isolation, the success of the applications was evaluated by pacing along the ablation line at 10 mA, 2 ms pulse width. Lesions were considered successful if loss of local capture was achieved. Results Out of 645 applications, 561 were successful and 84 were unsuccessful. Compared to the unsuccessful ablation points, the successful applications were shorter (p = 0.0429) and had a larger local impedance drop (p<0.0001). There was no difference between successful and unsuccessful applications in terms of mean contact force (p = 0.8571), force-time integral (p = 0.0699) and contact force range (p = 0.0519). The optimal cut-point for the local impedance drop indicating successful lesion formation was 21.80 Ohms on the anterior wall [AUC = 0.80 (0.75–0.86), p<0.0001], and 18.30 Ohms on the posterior wall [AUC = 0.77 (0.72–0.83), p<0.0001]. A local impedance drop larger than 21.80 Ohms on the anterior wall and 18.30 Ohms on the posterior wall was associated with an increased probability of effective lesion creation [OR = 11.21, 95%CI 4.22–29.81, p<0.0001; and OR = 7.91, 95%CI 3.77–16.57, p<0.0001, respectively]. Conclusion The measurement of the local impedance may predict optimal lesion formation. A local impedance drop > 21.80 Ohms on the anterior wall and > 18.30 Ohms on the posterior wall significantly increases the probability of creating a successful lesion.

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Di Cori ◽  
L Segreti ◽  
G Zucchelli ◽  
S Viani ◽  
F Tarasco ◽  
...  

Abstract Background Contact force catheter ablation is the gold standard for treatment of atrial fibrillation (AF). Local tissue impedance (LI) evaluation has been recently studied to evaluate lesion formation during radiofrequency ablation. Purpose Aim of the study was to assess the outcomes of an irrigated catether with LI alghorithm compared to contact force (CF)-sensing catheters in the treatment of symptomatic AF. Methods A prospective, single-center, nonrandomized study was conducted, to compare outcomes between CF-AF ablation (Group 1) and LI-AF ablation (Group 2). For Group 1 ablation was performed using the Carto 3© System with the SmartTouch SF catheter and, as ablation target, an ablation index value of 500 anterior and 400 posterior. For Group 2, ablation was performed using the Rhythmia™ System with novel ablation catheter with a dedicated algorithm (DirectSense) used to measure LI at the distal electrode of this catheter. An absolute impedance drop greater than 20Ω was used at each targeted. According to the Close Protocol, ablation included a point by point pulmonary vein isolation (PVI) with an Inter-lesion space ≤5 mm in both Groups. Procedural endpoint was PVI, with confirmed bidirectional block. Results A total of 116 patients were enrolled, 59 patients in Group 1 (CF) and 57 in Group 2 (LI), 65 (63%) with a paroxismal AF and 36 (37%) with a persistent AF. Baseline patients features were not different between groups (P=ns). LI-Group showed a comparable procedural time (180±89 vs 180±56, P=0.59) but with a longer fluoroscopy time (20±12 vs 13±9 min, P=0.002). Wide antral isolation was more often observed in CF-Group (95% vs 80%, P=0.022), while LI-Group 2 required frequently additional right or left carina ablation (28% vs 14%, P=0.013). The mean LI was 106±14Ω prior to ablation and 92.5±11Ω after ablation (mean LI drop of 13.5±8Ω) during a median RF time of 26 [19–34] sec for each ablation spot. No steam pops or complications during the procedures were reported. The acute procedural success was 100%, with all PVs successfully isolated in all study patients. Regarding safety, only minor vascular complications were observed (5%), without differences between groups (p=0.97). During follow up, 9-month freedom from atrial fibrillation/atrial flutter/atrial tachycardia recurrence was 86% in Group 1 and 75% in Group 2 (P=0.2). Conclusions An LI-guided PV ablation strategy seems to be safe and effective, with acute and mid-term outcomes comparable to the current contact force strategy. LI monitoring could be a promising complementary parameter to evaluate not only wall contact but also lesion formation during power delivery. Procedural Outcomes Funding Acknowledgement Type of funding source: None


EP Europace ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1645-1652
Author(s):  
Mattias Duytschaever ◽  
Johan Vijgen ◽  
Tom De Potter ◽  
Daniel Scherr ◽  
Hugo Van Herendael ◽  
...  

Abstract Aims To evaluate the safety and effectiveness of pulmonary vein isolation in paroxysmal atrial fibrillation (PAF) using a standardized workflow aiming to enclose the veins with contiguous and optimized radiofrequency lesions. Methods and results This multicentre, prospective, non-randomized study was conducted at 17 European sites. Pulmonary vein isolation was guided by VISITAG SURPOINT (VS target ≥550 on the anterior wall; ≥400 on the posterior wall) and intertag distance (≤6 mm). Atrial arrhythmia recurrence was stringently monitored with weekly and symptom-driven transtelephonic monitoring on top of standard-of-care monitoring (24-h Holter and 12-lead electrocardiogram at 3, 6, and 12 months follow-up). Three hundred and forty participants with drug refractory PAF were enrolled. Acute effectiveness (first-pass isolation proof to a 30-min wait period and adenosine challenge) was 82.4% [95% confidence interval (CI) 77.4–86.7%]. At 12-month follow-up, the rate of freedom from any documented atrial arrhythmia was 78.3% (95% CI 73.8–82.8%), while freedom from atrial arrhythmia by standard-of-care monitoring was 89.4% (95% CI 78.8–87.0%). Freedom fromrepeat ablations by the Kaplan–Meier analysis was 90.4% during 12 months of follow-up. Of the 34 patients with repeat ablations, 14 (41.2%) demonstrated full isolation of all pulmonary vein circles. Primary adverse event (PAE) rate was 3.6% (95% CI 1.9–6.3%). Conclusions The VISTAX trial demonstrated that a standardized PAF ablation workflow aiming for contiguous lesions leads to low rates of PAEs, high acute first-pass isolation rates, and 12-month freedom from arrhythmias approaching 80%. Further research is needed to improve the reproducibility of the outcomes across a wider range of centres. Clinical trial registration: ClinicalTrials.gov, number NCT03062046, https://clinicaltrials.gov/ct2/show/NCT03062046.


2013 ◽  
Vol 34 (suppl 1) ◽  
pp. P491-P491
Author(s):  
M. Kimura ◽  
S. Sasaki ◽  
D. Horiuchi ◽  
K. Sasaki ◽  
S. Owada ◽  
...  

2017 ◽  
Vol 58 (6) ◽  
pp. 880-884 ◽  
Author(s):  
Christian Blockhaus ◽  
Patrick Müller ◽  
Stephan vom Dahl ◽  
Silke Leonhardt ◽  
Dieter Häussinger ◽  
...  

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
D De Campos ◽  
L Puga ◽  
P Sousa ◽  
N Antonio ◽  
L Elvas

Abstract Funding Acknowledgements Type of funding sources: None. Introduction Ablation Index (AI) software has been associated with better freedom from atrial arrhythmias after pulmonary vein isolation (PVI) for paroxysmal atrial fibrillation (AF). There is conflicting data regarding the relationship between high sensitivity cardiac Troponin I (Hs-cTnI) and arrhythmia recurrence. The objective was to evaluate the impact of AI on Hs-cTnI level and on ablation effectiveness quotient (AEQ) and to assess if these markers are predictors of arrhythmia recurrence.  Methods Prospective observational study of consecutive patients referred for PVI for paroxysmal AF ablation from October 2017 to June 2018 according to a pre-specified AI protocol. Procedural endpoints and 2-year follow-up outcomes were assessed and compared to a retrospective cohort of conventional PVI contact-force-guided group .  Results A total of 56 patients were included: 29 patients the AI group and 27 patients in the control group. The mean age was 60.5 ± 10.3 years, 48% males. Left ventricular ejection fraction (60 ± 6 % AI vs 61 ± 5 % control, P = 0.07) and left atrium diameter (43 ± 7 mm AI vs 44 ± 6 mm control, P = 0.58) were comparable between groups. First-pass isolation was shown to be higher in the AI group (79% AI vs 44%, p= 0.01). Mean number of radiofrequency applications was lower in the AI group (93 ± 24 vs 111 ± 30, P = 0.02). Average contact-force was similar between groups (17.6 ± 4.1 g vs 22.6 ± 10.7 g, P =0.166). Patients that performed PVI guided by the AI had lower Hs-cTnI (1815 ± 1146 ng/L vs 3274 ± 1696 ng/L, p &lt; 0.001) and lower AEQ (1.01 ± 0.7 ng/L/s vs 1.51 ± 0.7 ng/L/s, P = 0.011) compared to patients in the control group. During a mean follow-up of 26 ± 11 months, AF recurrence was documented in 10.3% of patients in the AI group and 22.2% in the control group (P = 0.223). Neither Hs-cTnI nor AEQ levels were predictors of arrhythmia recurrence.  Conclusions These data suggest that AI-guided catheter ablation is associated with reduced levels of of Hs-cTnI and AEQ. Neither Hs-cTnI and AEQ should be used to predict arrhythmia recurrence. Abstract Figure.


EP Europace ◽  
2015 ◽  
Vol 17 (6) ◽  
pp. 877-883 ◽  
Author(s):  
J.-B. le Polain de Waroux ◽  
R. Weerasooriya ◽  
K. Anvardeen ◽  
C. Barbraud ◽  
S. Marchandise ◽  
...  

Author(s):  
David Tomlinson ◽  
Katie Biscombe ◽  
John True ◽  
Joanne Hosking ◽  
Adam Streeter

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.


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