doi:10.3389/fphys.2020.598314engChauhan, V.S.Martínez, J.P.van der Heyden, M.A.G.Commentary: Increased Beat-to-Beat Variability of T-Wave Heterogeneity Measured From Standard 12-Lead Electrocardiogram Is Associated With Sudden Cardiac Death: A Case-Control StudyART-2020-121101The electrocardiogram (ECG) reflects the electrical activity within the heart. Following the discovery of the small electrical signals in the human heart, the Dutch scientist Willem Einthoven developed sensitive methods for detecting them and recognized their clinical implications (Kligfield, 2002). For his contributions Willem Einthoven, whose scientific roots originated from the Utrecht physiology department (Einthoven, 1885), was awarded the Nobel Prize in 1924. Since then, many enigmas of the ECG have been solved and its intricate information carries valuable clues for clinical decision making. In vivo mapping studies have established that spatial heterogeneity in repolarization is a requisite for re-entrant ventricular arrhythmias by effecting unidirectional conduction block. Important modulators of spatial heterogeneity of repolarization include autonomic tone, ischemia, heart rate and premature or ectopic beats, which can produce temporal heterogeneity in the order of seconds, minutes, or hours depending on their time-constants. In the contemporary era of dynamic surface electrocardiography, a formidable challenge is quantifying spatiotemporal repolarization heterogeneity with sufficient fidelity to image the arrhythmogenic myocardial substrate and thereby provide indices for a patient’s risk of arrhythmic death (Laguna et al., 2016). Hekkanen et al. (2020) performed a large case-control study of 200 victims...2020http://zaguan.unizar.es/record/9718910.3389/fphys.2020.598314http://zaguan.unizar.es/record/97189oai:zaguan.unizar.es:97189info:eu-repo/grantAgreement/ES/DGA-FSE/T39-20R-BSICoS groupinfo:eu-repo/grantAgreement/ES/MICINN/PID2019-104881RB-I00FRONTIERS IN PHYSIOLOGY 11 (2020), 598314 [3 pp]byhttp://creativecommons.org/licenses/by/3.0/es/info:eu-repo/semantics/openAccess