20.500.12556/RUL-182662 Cardiac ablation effectiveness through intracardiac electrogram analysis and numerical modelling doctoral dissertation Obravnava učinkovitosti srčne ablacije z analizo znotrajsrčnih elektrogramov in numeričnim modeliranjem Catheter ablation is a cornerstone treatment for atrial fibrillation, aiming to eliminate arrhythmogenic tissue by creating lesions in a pulmonary vein isolation procedure. Despite widespread clinical use, assessing lesion completeness remains challenging, often leading to ineffective ablation or unnecessary collateral adjacent tissue damage. This research focuses on the evaluation of lesion creation using intracardiac electrograms (iEGMs) analysis and numerical modelling to improve real-time lesion assessment, with an emphasis on lesions created by pulsed field ablation (PFA). This thesis combines preclinical and early clinical data with computational modelling (two-dimensional, monodomain) to simulate iEGM generation after PFA. Bipolar and unipolar iEGMs were recorded before and after ablation using standard electrophysiological recording equipment. Changes in iEGM amplitude and morphology were analysed using discrete wavelet transform (DWT) to separate the depolarization from the current of injury (COI) components of iEGMs. A clear distinction between transmural and nontransmural lesions in unipolar iEGM dynamics after PFA was found, particularly in the low-frequency band (1–16 Hz) - COI, which showed also a strong correlation with gross pathology confirmed lesion size. Numerical modelling supported the empirical findings by replicating key observations made during and after PFA in preclinical and clinical settings. These simulations further provided mechanistic insights into observed iEGMs changes due to chronic lesion formation and transient (reversible) effects, that occur after PFA. This work demonstrates that COI, derived from unipolar iEGMs, may have a predictive value for determining lesion transmurality and lesion volume after PFA. The results lay the foundation for developing real-time feedback tools to guide ablation procedures and optimize PFA delivery. Additionally, the integration of proposed signal processing and numerical modelling provides a comprehensive framework to support innovation in cardiac ablation technology. This thesis contributes to bridging the gap between changes in iEGMs and clinical decision-making in electrophysiology procedures using PFA. Katetrska ablacija je temeljna metoda zdravljenja atrijske fibrilacije, katere cilj je odstranjevanje aritmogenega tkiva z ablacijskim lezijami, predvsem z izolacijo pljučnih ven. Kljub široki klinični uporabi pa ocenjevanje popolnosti in trajnosti lezij ostaja izziv, kar pogosto vodi do neuspešne ablacije ali nepotrebne poškodbe okoliškega tkiva. Z analizo znotraj srčnih elektrogramov (iEGM) in numeričnim modeliranjem smo ovrednotili nastanek ablacijskih lezij po ablaciji z elektroporacijo (PFA). V disertaciji smo združili eksperimentalne pred klinične podatke, zgodnje klinične podatke ter enostaven numerični model (2D, enodomenski), s katerim smo simulirali nastanek lezij in generacijo signalov iEGM po PFA. Bipolarne in unipolarne signale iEGM pred in po ablaciji smo zajeli z uporabo običajne elektrofiziološke opreme. Spremembe v amplitudi in morfologiji signalov iEGM smo analizirali z uporabo diskretne valčne transformacije (DWT), s katero smo ločili depolarizacijsko (sprožitev akcijskega potencial) komponento od komponente toka poškodbe (COI). V dinamiki COI iz unipolarnih signalov iEGM, predvsem v nizkofrekvenčnem območju (1–16 Hz), smo pokazali jasno razliko med transmuralnimi (poškodba se razteza preko celotne debeline stene) in netransmuralnimi lezijami po PFA. Dvig COI je dobro koreliral tudi z velikostjo lezije pridobljene z makroskopsko patološko preiskavo prašičjega srčnega tkiva. Z numeričnim modelom smo potrdili ključna empirična opažanja v signalih iEGM med in po PFA, s čimer smo pojasnili mehanizem sprememb v signalih iEGM, ki nastanejo zaradi trajne tvorbe lezij ali prehodnih (reverzibilnih) učinkov po PFA. Z delom v okviru doktorata smo dokazali, da COI dobro korelira s transmuralnostjo in velikostjo lezij po PFA. Rezultati predstavljajo osnovo za razvoj kliničnih orodij, ki bi lahko optimizirali dovajanje PFA energije. Poleg tega integracija predlaganega procesiranja signalov iEGM in modeliranja ponuja celovit okvir za podporo inovacijam na področju srčne ablacije. Disertacija prispeva k razumevanju sprememb v signalih iEGM in kliničnemu odločanju pri zdravljenju motenj srčnega ritma z uporabo PFA. intra-cardiac electrocardiogram atrial fibrillation radiofrequency ablation cardiac ablation by electroporation current-induced damage to cardiac muscle tissue doctoral degrees znotraj srčni elektrogram preddvorna fibrilacija radio frekvenčna ablacija srčna ablacija z elektroporacijo tok poškodbe srčnomišičnega tkiva doktorati true false false J. Štublar Angleški jezik Slovenski jezik Doktorsko delo/naloga 2026-05-20 12:05:01 2026-05-20 12:05:15 2026-07-13 15:08:21 0000-00-00 00:00:00 2026 0 Ljubljana 2026 Ljubljana Str. XXVII, 105, [45] str. pril. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 602.621:616.12-008.318(043.3) 52241 284611843 Stublar_Jernej_-_Obravnava_ucinkovitosti_srcne_ablacije_z_analizo_znotrajsrcnih_elektrogramov_in.pdf Stublar_Jernej_-_Obravnava_ucinkovitosti_srcne_ablacije_z_analizo_znotrajsrcnih_elektrogramov_in.pdf 1 5E3F070E7A2236805BE6104D46628DE2 9689472dce48861d64a7636f44616b746f03c85b1c41983f9af651ce8b7c3061 15118981-5433-11f1-b0ab-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=234124 Fakulteta za elektrotehniko 0 0 0