Modelling the dynamics of angles of human R-R intervals

Area of Science:

• Cardiology
• Physiology
• Nonlinear Dynamics

Background:

• Heart rate variability (HRV) is a valuable physiological measure.
• Analyzing HRV data in young, healthy individuals can reveal underlying physiological dynamics.
• Previous research has explored various methods for HRV analysis.

Purpose of the Study:

• To investigate the geometric structure of heart rate variability (HRV) data.
• To analyze the components of R-R intervals, specifically angles and radii.
• To determine if a deterministic structure exists within these HRV components.

Main Methods:

• Decomposition of HRV data into angular and radial components.
• Filtering of frequency ranges below 0.05 Hz from the angle data.
• Application of a proposed model for periodic self-oscillators to angle dynamics.

Main Results:

• A highly deterministic structure was observed in the map of successive angles for most subjects at rest.
• No obvious low-dimensional structure was found in the map of successive radii.
• The dynamics of the angles were successfully modeled using a recently proposed model for forced self-oscillators.

Conclusions:

• The angular component of HRV, after filtering, exhibits significant deterministic properties in healthy individuals.
• The radial component of HRV does not show a clear low-dimensional structure.
• A model for periodic self-oscillators can effectively describe the observed dynamics in HRV angles.