TPTE and Prolonged QT interval: TpTe has been identified as a marker of arrhythmogenic events in various patient populations, including those with hypertrophic cardiomyopathy, Brugada syndrome, or reduced LVEF due to any cause.20, 21, 22 Yamaguchi et al13 found that the TpTe/QT ratio can predict torsades de pointes tachycardias in patients with long QT syndrome.