What Researchers Did
Researchers evaluated how instantaneous beat-to-beat variability (SD1) and heart rate dynamics fractality (alpha1) changed during hyperbaric hyperoxia in ten divers.
What They Found
In ten divers exposed to hyperbaric hyperoxia (PO2 235 kPa) at 2.5 ATA for 60 minutes, instantaneous beat-to-beat variability (SD1) and high frequency (HF) power significantly increased. Concurrently, the fractality of heart rate dynamics (alpha1) decreased, and while SD1 and HF power correlated significantly, both correlated inversely with alpha1.
What This Means for Canadian Patients
For Canadian patients undergoing hyperbaric oxygen therapy or exposed to similar conditions, monitoring instantaneous beat-to-beat variability (SD1) could offer a reliable way to assess vagal tone. This alternative measurement may be particularly useful when standard heart rate variability assessments are challenging due to non-stationary conditions.
Canadian Relevance
This study has no direct Canadian connection.
Study Limitations
The study's findings are based on a small sample size of ten divers, which may limit the generalizability of the results to broader patient populations.