title: New descriptors of T-wave morphology are independent of heart rate.
abstract: T-wave morphology descriptors are sensitive to drug-induced changes and may be a useful addition to the QT interval in cardiac safety trials. Intrasubject heart rate dependence of T-wave morphology was investigated in a sample of 39 healthy individuals. Ten-second electrocardiograms were obtained from daytime Holter recordings. Duration parameters (QT, ToTe, TpTe, and others), a number of basic T-wave morphology parameters (amplitude, area, and others) as well as advanced morphology descriptors (asymmetry, flatness, and others) were measured automatically. Heart rate dependence was examined by means of analysis of covariance. The results showed clear heart rate dependence for the QT interval (R(2) = 0.53-0.57) and a moderate degree of heart rate dependence for the basic morphology parameters (amplitude, area, and others) (R(2) = 0.17-0.42). Both the advanced T-wave descriptors (asymmetry, flatness, and others), ToTe intervals and TpTe intervals, were practically independent of heart rate (R(2) = 0-0.08), making heart rate correction unnecessary for these parameters.
authors.affiliation: Department of Health Science and Technology, Aalborg University, Aalborg, Denmark. mpa@hst.aau.dk
authors.forename: Mads P
authors.initials: MP
authors.lastname: Andersen
authors.forename: Joel Q
authors.initials: JQ
authors.lastname: Xue
authors.forename: Claus
authors.initials: C
authors.lastname: Graff
authors.forename: Jørgen K
authors.initials: JK
authors.lastname: Kanters
authors.forename: Egon
authors.initials: E
authors.lastname: Toft
authors.forename: Johannes J
authors.initials: JJ
authors.lastname: Struijk
mesh_terms: D000465:Algorithms; D016477:Artifacts; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D010363:Pattern Recognition, Automated / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity