Discrimination of herg carrier from non-carrier adult patients with borderline prolonged QTc interval

Ten to fifteen percent of individual with the hereditary long-QT syndrome (LQTS) involving the human ether-a-go-go related gene (HERG) do not have an abnormal QT prolongation but are at risk of lethal arrhythmic event. We investigated the phenotypic T-wave morphology for the identification of patients with HERG mutations. The standard 12-lead ECGs from carrier and non-carrier LQT2 patients were digitized and the RR intervals and T-waves were quantified using QT/QTc, QT apex, T-wave amplitude, ascending (alpha_L) and its descending slopes (alpha_R). A logistic regression model selected 3 parameters for the classification of the groups: QT, RR and alpha_L. The model provided 92.7% sensitivity and 90.0 % specificity. The information within the T-wave morphology is complementary to the information of repolarization duration. Abnormal T-wave morphology is a phenotypic expression of the HERG mutation in adult LQTS patient