T-wave patterns associated with the hereditary long QT syndrome

Mutations involving 6 different ion-channel genes have been identified in subjects with the hereditaryLong QT Syndrome. These gene mutations result in structural and functional changes in ion-channel proteins withresultant alterations in potassium and sodium repolarization currents that affect the morphologic features ofelectrocardiographic repolarization. This review highlights the genotype-phenotype associations related toventricular repolarization that have been reported in the LQTS literature, with particular focus on ECG T-wavepatterns in LQT1, LQT2, and LQT3 genotypes.