Beat‐to‐Beat QT Dynamics in Healthy Subjects

摘要

Measures of QT dynamics express repolarization abnormalities that carry prognostic information, but the reproducibility of beat‐to‐beat QT dynamics has never been established. The QT interval is prolonged at night, but how the circadian rhythm and heart rate influence the dynamic QT measurements is still unsettled. The aims of the present study were: (1) to describe the reproducibility of beat‐to‐beat QT dynamics with respect to intrasubject, between‐subject, and between‐observer variability and (2) to describe the normal range, circadian variation, and heart rate dependence of QT dynamics.