Fig. 2: ECG response under simulated night-shift and constant routine.
From: Distinct circadian mechanisms govern cardiac rhythms and susceptibility to arrhythmia
A Schematic of 6-day laboratory session with simulated day-shift (left) and night-shift (right) routines (n = 7 individuals/group21). B, C ECG parameters recorded during mid-day (pink) and mid-night (green) showed a rapid reversal of RR and QT interval rhythms, but not that of PRseg in response to the switch to night-shift behavioral routine. Two-way ANOVA with repeated measures, colored asterisks indicate the difference from day 1. D Hourly binned z-scored group data and sinusoid fits from day- (orange) and night-shift (blue) conditions. Data presented as group mean ± SEM. E, F Timing (acrophase) of individual rhythm peaks relative to lights on (i.e., start of constant routine) (E) or external clock time (F). Asterisks indicate differences between groups (Watson–Williams test). *P < 0.05, **P < 0.01, ***P < 0.001. Source data and statistical details are provided as a Source Data File.
