000170461 001__ 170461 000170461 005__ 20260422085545.0 000170461 0247_ $$2doi$$a10.1007/s10840-026-02288-9 000170461 0248_ $$2sideral$$a148970 000170461 037__ $$aART-2026-148970 000170461 041__ $$aeng 000170461 100__ $$aSales-Belles, Clara$$uUniversidad de Zaragoza 000170461 245__ $$aReal-time assessment of inter and intraventricular synchrony in cardiac resynchronization therapy with left bundle branch pacing using ECGi and low-frequency QRS analysis 000170461 260__ $$c2026 000170461 5060_ $$aAccess copy available to the general public$$fUnrestricted 000170461 5203_ $$aIntroduction: Left bundle branch pacing (LBBP) is an alternative to conventional biventricular pacing for cardiac resynchronization therapy (CRT). Methods: A 76-year-old male was referred for CRT via left bundle branch pacing (LBBP). We present the real-time characterization of the transition from intrinsic left bundle branch block (LBBB) to sequential pacing modalities: right ventricular septal pacing (RVSP), left ventricular septal pacing (LVSP), and finally LBBP. Epicardial activation maps from electrocardiographic imaging (ECGi) and low-frequency (LF) QRS analysis were used to provide complementary insights into interand intraventricular synchrony. Results: LVSP, LBBP, and anodal capture improved activation compared with baseline, with LBBP achieving the greatest improvements in interventricular and LV intraventricular synchrony despite higher RV dispersion. Conclusion: These findings highlight ECGi and LF QRS as valuable tools to guide CRT. 000170461 536__ $$9info:eu-repo/grantAgreement/ES/AEI/PID2021-128972OA-I00$$9info:eu-repo/grantAgreement/ES/DGA/LMP 94-21$$9info:eu-repo/grantAgreement/ES/DGA/T39-23R$$9info:eu-repo/grantAgreement/ES/MICINN/AEI/CNS2022-135899$$9info:eu-repo/grantAgreement/ES/MICINN/PID2022-140556OB-I00$$9info:eu-repo/grantAgreement/ES/MICINN/RYC2019-027420-I$$9info:eu-repo/grantAgreement/EUR/MICINN/TED2021-130459B-I00 000170461 540__ $$9info:eu-repo/semantics/openAccess$$aby$$uhttps://creativecommons.org/licenses/by/4.0/deed.es 000170461 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion 000170461 700__ $$0(orcid)0000-0003-3183-4107$$aMincholé, Ana$$uUniversidad de Zaragoza 000170461 700__ $$aCabrera-Ramos, Mercedes$$uUniversidad de Zaragoza 000170461 700__ $$aMelero-Polo, Jorge$$uUniversidad de Zaragoza 000170461 700__ $$0(orcid)0000-0002-1960-407X$$aPueyo, Esther$$uUniversidad de Zaragoza 000170461 700__ $$aRamos Maqueda, Javier$$uUniversidad de Zaragoza 000170461 7102_ $$11007$$2610$$aUniversidad de Zaragoza$$bDpto. Medicina, Psiqu. y Derm.$$cArea Medicina 000170461 7102_ $$15008$$2800$$aUniversidad de Zaragoza$$bDpto. Ingeniería Electrón.Com.$$cÁrea Teoría Señal y Comunicac. 000170461 773__ $$g(2026), [6 pp.]$$pJ. Interv. Card. Electrophysiol.$$tJOURNAL OF INTERVENTIONAL CARDIAC ELECTROPHYSIOLOGY$$x1383-875X 000170461 8564_ $$s2662310$$uhttps://zaguan.unizar.es/record/170461/files/texto_completo.pdf$$yVersión publicada 000170461 8564_ $$s2217702$$uhttps://zaguan.unizar.es/record/170461/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada 000170461 909CO $$ooai:zaguan.unizar.es:170461$$particulos$$pdriver 000170461 951__ $$a2026-04-22-08:32:54 000170461 980__ $$aARTICLE