Circadian Patterns of Heart Rate and Heart Rate Variability in Wake-up Stroke: Evidence of Parasympathetic...

Although ischemic stroke is associated with complex changes in the autonomic nervous system, the circadian patterns of heart rate (HR) and heart rate variability (HRV) in wake-up stroke (WUS) remain poorly understood. This study compared 24-hour heart rate and HRV patterns between patients with and without WUS.

This retrospective observational case-control study involved 104 patients with acute ischemic stroke (9 WUS, 95 non-WUS). HRV analysis was performed using a 14-day continuous electrocardiography patch monitor. Time- and frequency-domain HRV metrics were calculated, and 24-hour differences were assessed using generalized additive mixed models (GAMMs), adjusting for confounders.

WUS patients had significantly higher HRs (80.60 ± 12.49 vs. 73.22 ± 14.49 beats per minute, P < 0.001) and lower HRV-measured by SDNN (28.06 ± 21.68 vs. 39.70 ± 25.73 milliseconds, P < 0.001), RMSSD (15.78 ± 12.49 vs. 22.16 ± 19.22 milliseconds, P < 0.001), and pNN50 (1.03% ± 2.78% vs. 2.61% ± 5.15%, P < 0.001)-than non-WUS patients. GAMMs indicated that patients with WUS experienced significant autonomic dysregulation, characterized by higher HRs, lower HRV, and altered circadian rhythms compared to those with non-WUS. These differences were particularly evident during the early morning hours.

WUS patients exhibited distinct 24-hour HR and HRV profiles, characterized by higher HRs and reduced autonomic variability compared to non-WUS patients. These differences align with patterns typically associated with lower parasympathetic activity rather than elevated sympathetic tone.

WUS is associated with impaired autonomic regulation and disrupted circadian patterns of HR and HRV.