Sample, Fuzzy and Distribution Entropies of Heart Rate Variability: What Do They Tell Us on Cardiovascular Complexity?

This study compares different methods of measuring the complexity of heart rate variability (HRV). It looks at Sample Entropy (SampEn), Fuzzy Entropy (FuzzyEn), and Distribution Entropy (DistEn). The study analyzes how these measures change with postural changes (sitting vs. supine) and in individuals with spinal cord injuries (SCI). Postural changes are expected to primarily affect the randomness of HRV, while SCI may alter the underlying cardiovascular complexity. The findings suggest that DistEn measures cardiovascular complexity, while SampEn and FuzzyEn measure HRV randomness. Using these methods together provides a more complete understanding of cardiovascular dynamics.

• 1
  DistEn is affected by spinal cord lesions but not by postural changes, suggesting it measures cardiovascular complexity.
• 2
  SampEn and FuzzyEn are affected by postural changes but not spinal cord lesions, suggesting they measure HRV randomness.
• 3
  Multiscale analysis reveals differences between AB and SCI sitting participants at larger mFE scales and between postures in AB participants at shorter mSE scales.