170962 20260430151736.0 doi 10.1016/j.ijcard.2026.134502 sideral 149034 ART-2026-149034 eng Garatachea, Nuria Universidad de Zaragoza (orcid)0000-0001-8374-9081 Cardiac magnetic resonance tissue characterization in endurance athletes with paroxysmal atrial fibrillation phenotype (PAFIYAMA) 2026 Background Endurance athletes have an increased risk of atrial fibrillation (AF), and focal late gadolinium enhancement (LGE) is frequently detected on cardiac magnetic resonance (CMR); however, whether myocardial fibrosis or diffuse myocardial abnormalities underlie AF-related functional phenotypes remains unclear. We previously described a paroxysmal AF phenotype in male endurance athletes (PAFIYAMA), characterized by reduced forward flow despite preserved global systolic function; nonetheless, the underlying myocardial substrate remains unknown. Methods In this observational cross-sectional study, 63 competitive male endurance athletes (PAFIYAMA n = 22; controls n = 41) underwent CMR with cine imaging, LGE, native T1, extracellular volume fraction (ECV), and T2 mapping. Training load was derived from the Lifetime Total Physical Activity Questionnaire. Group comparisons and multivariable models adjusted for age, body mass index, training load, and peak exercise blood pressure. Results Focal LGE was present in 15/63 (24%) athletes and did not differ between PAFIYAMA and controls. Among LGE-positive athletes, enhancement was predominantly hinge-point/insertional (8/15, 53.3%) or limited septal intramyocardial (6/15, 40.0%), with one subepicardial lateral case (1/15, 6.7%). Athletes with LGE had larger indexed biventricular volumes but similar native T1, ECV, and T2. Compared with controls, PAFIYAMA athletes showed lower biventricular stroke volume indices and lower left ventricle mass, with a slightly lower LVEF that remained within the normal range, and no differences in LGE prevalence or mapping indices. Conclusions In endurance athletes with the PAFIYAMA phenotype, CMR tissue characterization does not support focal LGE or diffuse mapping abnormalities as the substrate of the functional phenotype; interpretation of LGE in athletes should integrate pattern and clinical context. Access copy available to the general public Unrestricted info:eu-repo/grantAgreement/ES/DGA-FSE/LMP24-18 info:eu-repo/semantics/embargoedAccess by-nc-nd https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Echevarría-Polo, Marcos Universidad de Zaragoza Hernández-Vicente, Adrián Universidad de Zaragoza (orcid)0000-0001-6025-5070 D'Ascenzi, Flavio Fabregat-Andrés, Óscar Grazioli, Gonzalo de la Guía-Galipienso, Fernando Sanchis-Gomar, Fabian 1006 245 Universidad de Zaragoza Dpto. Fisiatría y Enfermería Área Educación Física y Depor. 456 (2026), 134502 [4 pp.] Int. j. cardiol. INTERNATIONAL JOURNAL OF CARDIOLOGY 0167-5273 568438 http://zaguan.unizar.es/record/170962/files/texto_completo.pdf Postprint info:eu-repo/date/embargoEnd/2027-04-17 1467245 http://zaguan.unizar.es/record/170962/files/texto_completo.jpg?subformat=icon icon Postprint info:eu-repo/date/embargoEnd/2027-04-17 oai:zaguan.unizar.es:170962 articulos driver 2026-04-30-13:57:58 ARTICLE