Vpliv ablacije z ireverzibilno elektroporacijo v levem prekatu srca prašičev na prostorski ventrikularni gradient

KRAMBERGER, ŽIGA (avtor), Jarm, Tomaž (mentor)

V tej magistrski nalogi predstavljamo teoretično ozadje in rezultate analize vpliva ablacije z ireverzibilno elektroporacijo (angl. Pulsed Field Ablation, PFA) na prostorski ventrikularni gradient (angl. Spatial Ventricular Gradient, SVG). Vrednosti parametrov vektorja SVG smo izračunali iz vektorkardiogramov (VCG), rekonstruiranih iz 12-odvodnih signalov EKG. PFA je nova, hitro razvijajoča ablacijska tehnika, ki se že uspešno uporablja pri zdravljenju atrijske fibrilacije z izolacijo pljučnih ven, medtem ko je pri posegih na prekatih manj raziskana. Cilj naše raziskave je bil ugotoviti, ali se spremembe, ki jih PFA povzroči v signalu EKG, odražajo tudi v prostorskem ventrikularnem gradientu (SVG). SVG predstavlja poenostavljeno obravnavo električne aktivnosti srca, zato nas je zanimalo, ali lahko takšna obravnava zajame učinke PFA – zlasti majhne spremembe, razpršene v več odvodih, ki bi v posameznih odvodih morda ostale prezrte. Glavni vir podatkov so bili 12-odvodni signali EKG, posneti na petih poskusnih živalih (prašičih) v okviru predhodno opravljene študije. Pri vsaki poskusni živali je bilo dovedenih od pet do osem lezij, ki so se razlikovale po dozi PFA (številu vlakov ablacijskih pulzov) in anatomski lokaciji znotraj levega prekata; amplituda pulzov je bila pri vseh lezijah 1500 V. Pri analizi SVG smo uporabili odprtokodni programski paket Braveheart, s katerim smo obdelali neobdelane 15 sekundne posnetke EKG pred ablacijo (20 s pred začetkom PFA) in po njej (20, 60, 120 in 240 s po koncu PFA), ter tako pridobili vrednosti parametrov SVG (magnituda, azimut in elevacija). Rezultati analize sprememb SVG po dovajanju PFA so pokazali statistično značilen vpliv PFA na magnitudo SVG že pri globalni analizi vseh lezij skupaj. Pri analizi po posameznih živalih smo zaznali kumulativni učinek na magnitudo in azimut SVG. Opazili smo tudi, da je bil vpliv PFA na parametre SVG odvisen od uporabljene doze, saj smo zaznali statistično značilen vpliv pri dozah 8 in 16 vlakov. Odziv se je razlikoval tudi glede na lokacijo znotraj levega prekata, pri čemer so izrazito izstopale lezije v apeksu z največjimi spremembami parametrov SVG po koncu PFA glede na vrednosti pred začetkom PFA. Pri prenosu ugotovitev na človeka je potrebna previdnost zaradi anatomskih razlik med prašičem in človekom ter razmeroma majhnega vzorca podatkov. Raziskava kljub temu pokaže, da ima analiza SVG pri ocenjevanju učinkov PFA velik potencial, in nakazuje potrebo po nadaljnjih raziskavah na tem področju.

• Jezik: Slovenski jezik
• Ključne besede: ablacija z ireverzibilno elektroporacijo, vektorkardiografija, prostorski ventrikularni gradient, levi prekat, lezija, miokard
• Vrsta gradiva: Magistrsko delo/naloga
• Tipologija: 2.09 - Magistrsko delo
• Organizacija: FE - Fakulteta za elektrotehniko
• Leto izida: 2026
• PID: 20.500.12556/RUL-186958
• COBISS.SI-ID: 291564803
• Datum objave v RUL: 08.09.2026

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Effects of Left Ventricular Pulsed Field Ablation in Swine on the Spatial Ventricular Gradient

Izvleček

In this master's thesis, we present the theoretical background and results of an analysis of the effect of pulsed field ablation (PFA) on the spatial ventricular gradient (SVG). The values of the SVG vector parameters were calculated from vectorcardiograms (VCG) reconstructed from 12-lead ECG signals. PFA is a novel and rapidly developing ablation technique already used successfully in the treatment of atrial fibrillation through pulmonary vein isolation, whereas it remains less investigated in ventricular procedures. The aim of our study was to determine whether the changes that PFA induces in the ECG signal are also reflected in the spatial ventricular gradient (SVG). The SVG represents a simplified representation of the heart's electrical activity, so we were interested in whether such an approach can capture the effects of PFA - in particular small changes distributed across several leads that might otherwise go unnoticed in individual leads. The main data source consisted of 12-lead ECG signals recorded in five experimental animals (pigs) as part of a previously conducted study. Between five and eight lesions were created in each animal, differing in PFA dose (the number of ablation pulse trains) and in anatomical location within the left ventricle; the pulse amplitude was 1500 V for all lesions. For the SVG analysis, we used the open-source software package Braveheart, with which we processed unprocessed 15-second ECG recordings from before ablation (20 s before the onset of PFA) and after it (20, 60, 120, and 240 s after the end of PFA), thereby obtaining the values of the SVG parameters (magnitude, azimuth, and elevation). The results of the analysis of SVG changes following PFA showed a statistically significant effect of PFA on SVG magnitude already in the global analysis of all lesions combined. In the analysis of individual animals, we observed a cumulative effect on SVG magnitude and azimuth. We also observed that the effect of PFA on the SVG parameters depended on the applied dose, as a statistically significant effect was detected at doses of 8 and 16 pulse trains. The response also differed according to location within the left ventricle, with lesions in the apex standing out markedly, showing the largest changes in the SVG parameters after PFA relative to the values before its onset. When translating these findings to humans, caution is needed because of the anatomical differences between pigs and humans and the relatively small data sample. Nevertheless, the study shows that SVG analysis has considerable potential for assessing the effects of PFA and points to the need for further research in this field.

• Ključne besede: pulsed field ablation, vectorcardiography, spatial ventricular gradient, left ventricle, lesion, myocardium