Quantitative Aspects of Ventricular Repolarization.: Relationship Between Three-Dimensional T Wave Loop Morphology and Scalar QT Dispersion

摘要: Introduction: QT dispersion assesses repolarization inhomogeneity on 12-lead standard ECG. However, the implications of electrical cardiac vector during phase (the T wave loop) with genesis this phenomenon are unknown. Methods and Results: The aim study was to explore conventional resting ECG corresponding morphology spatial three-dimensional (3-D) loop in 25 normals subjects, 30 postmyocardial infarction (Ml) patients, 17 individuals congenital long syndrome (LQTS). Standard XYZ leads were simultaneously digitized (250 Hz) automatically analyzed. Ventricular estimated by range (RAN12o) deviation (SD12o) 12 rate corrected QTo intervals (between Q onset offset). Spatial loops extracted from data analyzed a 3-D algorithm which provides quantitative parameters related morphology. All scalar measurements significantly larger two pathological populations; however none them could discriminate post-MI LQTS groups (RAN12o = 33.3, 61.4, 62.7 ms respectively, for three populations). Conversely, loss planarity an increased roundness observed groups, former effect more pronounced (P 0.04 compared post-MI) latter group 0.02 LQTS). Furthermore, multiple regression principal component analyses showed that independently involved dispersion. Conclusion: Changes associated identified. These changes different substrates inhomogeneity. use technique assess may bring additional information intrinsic nature disorder.