Increased QT Interval Variability in 3 Recently Concussed Athletes: An Exploratory Observation

摘要

Context:The QT interval variability index (QTVI) is a noninvasive measure of beat-to-beat fluctuations of the QT interval as seen from a single electrocardiographic lead. It represents the relationship between the respective variabilities of the QT and R-R intervals. Recently, the QTVI was demonstrated to be an index of vagal cardiac autonomic modulation in resting conditions.