Functional significance of KCNH2 (HERG) K897T polymorphism for cardiac repolarization assessed by analysis of T-wave morphology.

Background: Although KCNH2 (HERG) K897T polymorphism has been shown to be associated with the QT interval measured from 12-lead electrocardiogram (ECG), the functional significance of K897T polymorphism has been debated. The aim of this study was to test whether the K897T polymorphism of the KCNH2 (HERG) gene coding for the rapidly activating delayed rectifier K+ channel influences cardiac repolarization assessed by principal component analysis (PCA) of T-wave morphology.

Methods: Twelve-lead ECGs were digitized and T-wave morphology was analyzed with a PCA method in a population consisting of 228 healthy middle-aged subjects (121 women and 107 men).