For the first time, Mirvis noticed a significant irregularity of the QT intervals in patients with acute myocarditis compared to the healthy population (Mirvis, 1985). Later, in 1990, Day et al. proposed a potential application of this inter-lead difference using standard 12-lead electrocardiograms (ECGs) (Day et al., 1990). Since then, numerous studies have investigated the differences between QT max and min in different ECG leads, entitled QT dispersion (QTd) (Day et al., 1990).Several studies have shown an association between death from a cardiac cause and QTd (Barr et al., 1994;Bazoukis et al., 2020;Naas et al., 1998). It should be noted that some findings have challenged this association. For example, QTd may decrease as a result of drug