Dössel, Olaf

Martínez Antón, Carmen

Unger, Laura Anna

English

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Analyzing the Effect of Catheter-Sheath Overlapping Status inLocal Impedance SimulationsCarmen Mart́ınez Antón1, Laura Anna Unger1, and Olaf Dössel11Karlsruhe Institute of Technology, Institute of Biomedical Engineering, Karlsruhe, GermanyBackgroundIn the heart, areas of scar and different levels offibrotic tissue have been identified as potentialdriving regions of arrhythmic activity. These ar-eas are typically characterized by magnetic reso-nance imaging or low voltage maps. Since boththe aforementioned modalities entail drawbackswhen concluding on the underlying substrate, lo-cal impedance (LI) measurements have gained at-tention recently. Intracavitary LI recordings canprovide the information required to locate regionsof pathologically altered substrate as changes inconductivity may indicate alterations in myocar-dial functionality. In this context, identifying thefactors contributing to the measured LI is a mat-ter of importance to provide accurate and reliableassessments. However, in clinical practice physi-cians face artifacts that flaw LI values, such as theoverlap between segments of the catheter and thesteerable sheath.ObjectiveTo identify the effect of different overlapping sta-tus between a steerable sheath and catheter seg-ments in LI measurements by means of in silicoexperiments.MethodsPrecise, three-dimensional models [1] of thecatheters IntellaNav MiFi™ OI and IntellaNavStablePoint™ (Boston Scientific, Marlborough,MA, USA) were developed.A steerable sheath was added varying its rela-tive position to the ablation catheter to changethe degree of overlap between both elementswere embedded into a blood box. Meshes weregenerated to simulate different combinations ofcatheter-sheath overlapping status with GMSH4.4.1. and a simulation environment predestinedfor impedance studies. Distinct conductivitieswere assigned to electrodes, insulators, and thesurrounding blood. Knowing the injected cur-rent between the tip and the proximal ring elec-trode, the simulation can be defined as a forwardproblem with a unique solution. Clinical studiesand in vitro experiments were performed at theStädtisches Klinikum Karlsruhe to validate thesimulation results with real sheath artifact prob-lems.ResultsA simulated trace of LI values while moving thesheath along the catheter is shown in Fig. 1. As itwas reported in clinical studies, LI measurementsincrease significantly when reaching the proximalring.Figure 1: LI values simulated trace as the distalsegment of the sheath overlaps the catheter Intel-laNav MiFi™ OI.DiscussionDuring an electrophysiological study, a steerablesheath is required to help with catheter stabilityand navigation. However, if the sheath overlapswith one or more of the electrodes, a significantdistortion occurs in the LI measurement. Compu-tational models help to understand and solve thisartifact, particularly in the boundary regions withmarginal but clinically significant LI alterations.References[1] S. Pollnow et al., “Mini electrodes on abla-tion catheters: Valuable addition or redun-dant information? insights from a computa-tional study,” Computational and Mathemati-cal Methods in Medicine, 2017.AcknowledgementThis Project has received funding from the Eu-ropean Union’s Horizon research and Innovationprogramme under the Marie Sk lodowska-Curiegrant agreement No. 860974.doi:10.5445/IR/1000138457 Atrial Signals 2021 Proceedings 10

Analyzing the Effect of Catheter-Sheath Overlapping Status in Local Impedance Simulations. Abstract

https://publikationen.bibliothek.kit.edu/1000138457/130450837

Analyzing the Effect of Catheter-Sheath Overlapping Status in Local Impedance Simulations. Abstract

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