108303 20230519145350.0 doi 10.1111/sms.13849 sideral 121141 ART-2021-121141 eng Milagro, J. (orcid)0000-0002-7842-9611 Estimation of the second ventilatory threshold through ventricular repolarization profile analysis 2021 Access copy available to the general public Unrestricted Under the hypothesis that sympathetic control of ventricular repolarization may change once the second ventilatory threshold (VT2) has been reached, a novel methodology for non-invasive VT2 estimation based on the analysis of the T wave from the electrocardiogram (ECG) is proposed, and potential underlying physiological mechanisms are suggested. 25 volunteers (33.4 ± 5.2 years) underwent an incremental power cycle ergometer test (25 W/minute). During the test, respiratory gas exchange and multi-lead ECG were acquired. The former was employed to determine VT2, used here as a reference, whereas the latter was used to compute the temporal profiles of an index of ventricular repolarization instability (dT) and its low-frequency (LF) oscillations (LFdT). The sudden increases observed in dT and LFdT profiles above an established heart rate threshold were employed to derive VT2 estimates, referred to as VT2dT and VT2LFdT, respectively. Estimation errors of -4.7 ± 25.2 W were obtained when considering VT2dT. Errors were lower than the one-minute power increment of 25 W in 68% of the subjects and lower than 50 W in 89.5% of them. When using VT2LFdT, estimation error was of 15.3 ± 32.4 W. Most of the subjects shared common characteristic dT and LFdT profiles, which could be reflecting changes in the autonomic control of ventricular repolarization before and after reaching VT2. The analysis of ventricular repolarization dynamics during exercise allows non-invasive ECG-based estimation of VT2, possibly in relation to changes in the autonomic control of ventricular electrical activity when VT2 is reached. info:eu-repo/grantAgreement/ES/DGA-FSE/LMP124-18 info:eu-repo/grantAgreement/ES/DGA-FSE/LMP44-18 info:eu-repo/grantAgreement/ES/DGA-FSE/T39-20R-BSICoS group info:eu-repo/grantAgreement/EUR/ERC-2014-StG-638284 info:eu-repo/grantAgreement/ES/MECD/FPU16-05879 info:eu-repo/grantAgreement/ES/MINECO/BES-2015-073694 info:eu-repo/grantAgreement/ES/MINECO-FEDER/RTI2018-097723-B-I00 info:eu-repo/grantAgreement/ES/MINECO/PID2019-105674RB-I00 info:eu-repo/semantics/openAccess All rights reserved http://www.europeana.eu/rights/rr-f/ 4.645 2021 SPORT SCIENCES 14 / 88 = 0.159 2021 Q1 T1 1.383 2021 Physical Therapy, Sports Therapy and Rehabilitation 2021 Q1 Orthopedics and Sports Medicine 2021 Q1 7.6 2021 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion Hernández-Vicente, A. Universidad de Zaragoza (orcid)0000-0001-6025-5070 Hernando, D. (orcid)0000-0002-1462-4880 Casajús, J.A. Universidad de Zaragoza (orcid)0000-0002-7215-6931 Garatachea, N. Universidad de Zaragoza (orcid)0000-0001-8374-9081 Bailón, R. Universidad de Zaragoza (orcid)0000-0003-1272-0550 Pueyo, E. Universidad de Zaragoza (orcid)0000-0002-1960-407X 1006 245 Universidad de Zaragoza Dpto. Fisiatría y Enfermería Área Educación Física y Depor. 5008 800 Universidad de Zaragoza Dpto. Ingeniería Electrón.Com. Área Teoría Señal y Comunicac. 31, 2 (2021), 339-349 Scand. j. med. sci. sports Scandinavian Journal of Medicine and Science in Sports 0905-7188 820488 http://zaguan.unizar.es/record/108303/files/texto_completo.pdf Postprint 2286839 http://zaguan.unizar.es/record/108303/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:108303 articulos driver 2023-05-18-13:26:13 ARTICLE