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Review
. 2022 Apr;63(3):749-758.
doi: 10.1007/s10840-022-01163-7. Epub 2022 Mar 24.

When local impedance meets contact force: preliminary experience from the CHARISMA registry

Francesco Solimene  1 , Valerio De Sanctis  2 , Ruggero Maggio  3 , Maurizio Malacrida  4 , Luca Segreti  5 , Matteo Anselmino  6 , Vincenzo Schillaci  1 , Massimo Mantica  7 , Marco Scaglione  8 , Antonio Dello Russo  9 , Filippo Maria Cauti  10 , Gianluca Zingarini  11 , Claudio Pandozi  12 , Marco Cavaiani  4 , Anna Ferraro  3 , Giampiero Maglia  13 , Giuseppe Stabile  1   14
Affiliations
Review

When local impedance meets contact force: preliminary experience from the CHARISMA registry

Francesco Solimene et al. J Interv Card Electrophysiol. 2022 Apr.

Abstract

Purpose: Highly localized impedance (LI) measurements during atrial fibrillation (AF) ablation have emerged as a viable real-time indicator of tissue characteristics and the consequent durability of the lesions created. We investigated the impact of catheter-tissue contact force (CF) on LI behavior during pulmonary vein isolation (PVI).

Methods: Forty-five consecutive patients of the CHARISMA registry undergoing de novo AF radiofrequency (RF) catheter ablation with a novel open-irrigated-tip catheter endowed with CF and LI measurement capabilities (Stablepoint™ catheter, Boston Scientific) were included.

Results: A total of 2895 point-by-point RF applications were analyzed (RF delivery time (DT) = 8.7±4s, CF = 13 ±±8 g, LI drop = 23 ±±7 Ω). All PVs were successfully isolated in an overall procedure time of 118 ±±34 min (fluoroscopy time = 13 ±±8 min). The magnitude of LI drop weakly correlated with CF (r = 0.13, 95% confidence interval (CI): 0.09 to 0.16, p < 0.0001), whereas both CF and LI drop inversely correlated with DT (r = -0.26, 95%CI: -0.29 to -0.22, p < 0.0001 for CF; r = -0.36, 95%CI: -0.39 to -0.33, p < 0.0001 for LI). For each 10 g of CF, LI drop markedly increased from 22.4 ± 7 Ω to 24.0 ± 8 Ω at 5 to 25 g CF intervals (5-14 g of CF vs 15-24 g of CF, p < 0.0001), whereas it showed smooth transition over 25 g (24.8 ± 7Ω at ≥ 25 g CF intervals, p = 0.0606 vs 15-24 g of CF). No major complications occurred during the procedures or within 30 days.

Conclusions: CF significantly affects LI drop and probable consequent lesion formation during RF PVI. The benefit of higher contact (> 25 g) between the catheter and the tissue appears to have less impact on LI drop.

Trial registration: Catheter Ablation of Arrhythmias With High Density Mapping System in the Real World Practice (CHARISMA). URL: http://clinicaltrials.gov/ Identifier: NCT03793998.

Keywords: Atrial fibrillation; Catheter ablation; Contact force; Lesion formation; Local impedance; PVI.

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Conflict of interest statement

M. Malacrida, M. Cavaiani are employees of Boston Scientific. The other authors have no conflict of interest to declare that are relevant to the content of this article.

Figures

Fig. 1
Fig. 1
A Identification of 7 ablation sites around the right (RPV) and left (LPV) pairs of pulmonary veins. Anterior superior: R1, L1. Anterior inferior: R2, L2. Inferior: R3, L3. Posterior inferior: R4, L4. Carina: R5, L5. Posterior superior: R6, L6. Superior: R7, L7. LIPV = left inferior pulmonary vein; LSPV = left superior pulmonary vein; RIPV = right inferior pulmonary vein; RSPV = right superior pulmonary vein. B Example of visualization of CF and DirectSense™ tool on the Rhythmia™ mapping system during ablation. C Point-by-point RF delivery created contiguous ablation spots encircling the PVs. The maximal inter-lesion distance between two neighboring lesions was set ≤ 6 mm and was automatically measured through the Autotag™ software. CF settings were at the individual operator’s discretion, within the range of 5 to 40 g
Fig. 2
Fig. 2
A Multidimensional relationship between RF delivery time, CF values, and LI drop values. B Radar plot showing the relationship between RF delivery time and CF values according to different degrees of LI drop. This Kiviat chart displays multivariate data (RF delivery time) with values represented on axes starting from the same point. The apexes of the Kiviat charts represent different CF intervals (5–14 g, 15–24 g, and ≥ 25 g), whereas the lines represent different degrees of LI drop (blue line for 10–19 Ω LI drop values, orange line for 20–29 Ω LI drop values and grey line for LI drop values ≥ 30 Ω). RF delivery time is represented according to CF and LI drop intervals. C Radar plot showing the relationship between RF delivery time and LI drop values according to different degrees of CF. This Kiviat chart displays multivariate data (RF delivery time) with values represented on axes starting from the same point. The apexes of the Kiviat charts represent different LI drop intervals (10–19 Ω, 20–29 Ω, and ≥ 30 Ω), whereas the lines represent different degrees of CF (blue line for 5–14 g CF values, orange line for 15–24 g CF values, and grey line for CF values ≥ 25 g). RF delivery time is represented according to CF and LI drop intervals
Fig. 3
Fig. 3
Details of relationships among the three key parameters: RF delivery time and LI drop according to different levels of CF (A); RF delivery time and CF according to different degrees of LI drop (B); and CF and LI drop according to different values of RF delivery time (C)
Fig. 4
Fig. 4
Details of the distribution of baseline LI (A), LI drop (B), RF delivery time (C), and CF values (D) according to location sites: anterior sites vs posterior sites, LPV sites vs RPV sites and inferior vs superior sites
Fig. 5
Fig. 5
Details of the distribution of RF applications, CF, ablated tissue impedance values, and RF delivery times according to location sites. This Kiviat chart displays multivariate data with values represented on axes starting from the same point. Each apex of the Kiviat charts represents a location site according with seven distinct sections of right (R) and left (L) pairs of PVs (anterior superior R1, L1; anterior inferior R2, L2; inferior R3, L3; posterior inferior R4, L4; carina R5, L5; posterior superior R6, L6; superior R7, L7). Blue, orange, and grey dots represent the mean LI drop values, CF values, and RF delivery time values according to location sites
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References

    1. Hindricks G, Potpara T, Dagres N, et al. ESC Scientific Document Group. 2020 ESC Guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association of Cardio-Thoracic Surgery (EACTS): the task force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Eur Heart J. 2020;ehaa612. - PubMed
    1. Saglietto A, Gaita F, De Ponti R, De Ferrari GM, Anselmino M. Catheter ablation vs. anti-arrhythmic drugs as first-line treatment in symptomatic paroxysmal atrial fibrillation: a systematic review and meta-analysis of randomized clinical trials. Front Cardiovasc Med. 2021;21(8):664647. doi: 10.3389/fcvm.2021.664647. - DOI - PMC - PubMed
    1. January CT, Wann LS, Calkins H, Chen LY, Cigarroa JE, Cleveland JC, Jr, Ellinor PT, Ezekowitz MD, Field ME, Furie KL, Heidenreich PA, Murray KT, Shea JB, Tracy CM, Yancy CW. 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. Heart Rhythm. 2019;16(8):e66–e93. doi: 10.1016/j.hrthm.2019.01.024. - DOI - PubMed
    1. Calkins H, Hindricks G, Cappato R, Kim YH, Saad EB, Aguinaga L, Akar JG, Badhwar V, Brugada J, Camm J, Chen PS, Chen SA, Chung MK, Cosedis Nielsen J, Curtis AB, Davies DW, Day JD, d'Avila A, Natasja de Groot NMS, Di Biase L, Duytschaever M, Edgerton JR, Ellenbogen KA, Ellinor PT, Ernst S, Fenelon G, Gerstenfeld EP, Haines DE, Haissaguerre M, Helm RH, Hylek E, Jackman WM, Jalife J, Kalman JM, Kautzner J, Kottkamp H, Kuck KH, Kumagai K, Lee R, Lewalter T, Lindsay BD, Macle L, Mansour M, Marchlinski FE, Michaud GF, Nakagawa H, Natale A, Nattel S, Okumura K, Packer D, Pokushalov E, Reynolds MR, Sanders P, Scanavacca M, Schilling R, Tondo C, Tsao HM, Verma A, Wilber DJ, Yamane T. 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation. Europace. 2018;20(1):e1–e160. doi: 10.1093/europace/eux274. - DOI - PMC - PubMed
    1. Segreti L, De Simone A, Schillaci V, et al. A novel local impedance algorithm to guide effective pulmonary vein isolation in atrial fibrillation patients: preliminary experience across different ablation sites from the CHARISMA pilot study [published online ahead of print, 2020 Jul 1]. J Cardiovasc Electrophysiol. 2020. 10.1111/jce.14647. - PubMed

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