Key result
Healthy men exhibit a ~23 ms shorter mean QTc interval than women alongside diurnal variability.
Why the study?
The pattern and relation of daily variability in QTc interval to heart rate variability remain poorly characterized.
Population
21 healthy subjects
Comparison
None, observational measurement of QT and QTc intervals over 24 hours
Design
Continuous measurement from three-channel 24-h Holter recordings
Follow-up
24 hours
Authors
Loading...
Captured external expert commentary on this paper, strongest first. Original sources are linked where available.
“A QTc value of 560 ms needs to be considered in the light of 24-hour monitoring data in healthy subjects which showed a mean maximum QTc of 511 ms in females (479 ms in males) and an intrasubject diurnal variation of 102 ms in females (88 in males).”
Morning QTc peaks may prompt time-adjusted norms in ECG interpretation; leaves open prospective validation for arrhythmia risk stratification.
Observational (n=21)
Absolute Event Rate: 434% vs 457%
p-value: p=< 0.0001
Molnár et al. (1996) conducted an observational in Healthy (n=21). 24-hour Holter monitoring was evaluated on Mean QTc interval (men vs women) (p=< 0.0001). Continuous 24-hour Holter monitoring in healthy subjects revealed significant diurnal QTc variability and a mean QTc interval of 434 ms in men versus 457 ms in women (p<0.0001).
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: