摘要：Background: Autonomic function has been linked to cognitive abilities in aging. Even
in non-clinical states, a certain variability in heart rhythm regulation can be measured
with QT dispersion (QTcD), an ECG marker of ventricular repolarization which has been
linked to autonomic function and cardiovascular health. QTcD has been shown to be
higher in individuals with mild cognitive impairment, and the highest in individuals with
Alzheimer’s disease. The goal of this study was to see if QTcD is associated with
cognitive performance in healthy individuals.
Methods: Sixty-three healthy inactive older adults (> 60 years) completed an extensive
cognitive assessment (including inhibition, divided attention, updating, working memory,
and processing speed), a physical fitness assessment, and underwent a resting ECG.
Results: After controlling for age, sex, and education, QTcD significantly predicted
global cognition (MoCA) scores (R
2 = 0.17, F(4.58) = 3.00, p < 0.03, β = −0.36).
Exploratory analysis on the MoCA subcomponents revealed a significant association
between the visual/executive subcomponent and QTcD (R
2 = 0.12, F(1.61) = 7.99,
p < 0.01, β = −0.34). In individuals with high QTcD, QTcD values were linked
to executive functions (R
2 = 0.37), processing speed (R
2 = 0.34), and dualtask performances (R
2 = 0.47). No significant associations were found within
the low QTcD group.
Conclusion: This study shows an association between ventricular repolarization (QTcD)
and cognitive performance, in particular speed and executive functions, in healthy older
adults. The results provide further support for linking autonomic heart regulation and
age-related cognitive changes, and suggest that deviations on ECG, even within-normal
range, could help detect early cognitive deficits.
关键词：cognition; ventricular repolarization dispersion; aging; cardiovascular health; autonomic function
