Circadian rhythm of the QT interval dispersion in healthy subjects. Correlation with heart rate variability circadian pattern

QT Intervals and QT Dispersion Determined from a 12‐Lead 24‐Hour Holter Recording in Patients with Coronary Artery Disease and Patients with Heart Failure

“…Abnormalities of the autonomic nervous system appear to be involved in the genesis of sudden cardiac death. The sympathovagal tone may affect QT variability in healthy subjects 7 and treatment with beta‐blockers in patients with heart failure is associated with a reduction in QT dispersion 8 indicating that sympathetic deactivation may cause decreased QT dispersion.…”

Circadian Variation in QT Dispersion Determined from a 12‐Lead Holter Recording: A Methodological Study of an Age‐ and Sex‐Stratified Group of Healthy Subjects

“…Circadian variation of QT dispersion in healthy subjects has been suggested by Ishida et al, 8 Molnar et al, 9 Lee et al, 10 Yetkin et al, 19 Batur et al, 20 Bilan et al, 21 and Bonnemeier et al, 22 but the results are contradictory and the studies have different setups in respect to number of leads used, measurement frequency, and whether heart rate correction of QT dispersion is used or not.…”

“…Similar to our observations a reduced number of leads resulted in lower values of QT dispersion. Ishida et al 8 and Bilan et al 21 demonstrated a circadian variation of QT dispersion with lower values at night, whereas Molnar et al 9 demonstrated higher values of QT dispersion at night compared to daytime. Michelucci et al 24 demonstrated no circadian variation in healthy subjects.…”

“…Malik et al 23 did not find any significant difference between day and night in a 12‐lead Holter recording. Ishida et al 8 and Bilan et al 21 used a three‐channel ECG recording system, and Molnar et al 9 used a two‐lead ECG recording system. Similar to our observations a reduced number of leads resulted in lower values of QT dispersion.…”

The Effects of Glucose Tolerance, Hypertension, and Race on Heart Rate Variability, QT Interval Duration, and Left Ventricular Hypertrophy in Overweight-Obese Adolescents

“…Few studies have examined relationships between QT Interval duration and HRV, and literature identified were more likely to examine these variables in conjunction with one another rather than in relation to one another (Bilan, Witczak, Palusinski, Ignatowicz, & Hanzlik, 2005). Circadian variation of autonomic tone is believed to affect QT Interval duration (Ishida, Nakagawa, Fujino, Yonemochi, Saikawa, & Ito, 1997).…”