New approach for visualization of relationships between RR and JT intervals

PLoS One. 2017 Apr 5;12(4):e0174279. doi: 10.1371/journal.pone.0174279. eCollection 2017.


This paper presents the concept of perfect matrices of Lagrange differences which are used to analyze relationships between RR and JT intervals during the bicycle ergometry exercise. The concept of the perfect matrix of Lagrange differences, its parameters, the construction of the load function and the corresponding optimization problem, the introduction of internal and external smoothing, embedding of the scalar parameter time series into the phase plane-all these computational techniques allow visualization of complex dynamical processes taking place in the cardiovascular system during the load and the recovery processes. Detailed analysis is performed with one person's RR and JT records only-but the presented techniques open new possibilities for novel interpretation of the dynamics of the cardiovascular system.

MeSH terms

  • Adult
  • Bicycling / physiology
  • Electrocardiography / methods
  • Exercise / physiology*
  • Heart / physiology*
  • Humans
  • Male
  • Time Factors

Grant support

Lithuanian University of Health Sciences is acknowledged for covering the open access publication fee. Financial support from the Lithuanian Science Council under project no. MIP078=15 is acknowledged.