Heart rate variability behavior at different stages of practice in Zen meditation: a study of the system dynamics using multiresolution analysis

The  dynamic  interactions  between  the  sympathetic  and  parasympathetic  branches  of  the  autonomic  nervous system (ANS) are responsible for the oscillations in heart rate known as heart rate variability (HRV). Thus, the importance of HRV as an indirect measure of the autonomic activity is widely known. Meditation is  perhaps  the  best  practice  to  investigate  the  intrinsic  properties  of  the  ANS,  since  it  involves  a  state  of  complete physical immobility and absence of voluntary efforts. In this study we analyzed HRV during Zen meditation  in  13  practitioners  with  varying  degrees  of  expertise.  Given  that  HRV  derives  from  a  set  of  rhythmic processes operating at different time-scales, a multiresolution analysis was performed. For each time  series  the  wavelet  variance  was  estimated  at  seven  discrete  scales  using  a  modified  version  of  the  discrete wavelet transform, the maximal overlap discrete wavelet transform (MODWT), and we performed a principal components analysis on this data set. We found evidences that different stages in the practice of Zen meditation can be characterized by specific patterns of cardiac variability that tend to evolve to a «low cost  mode  of  functioning»,  defined  by  the  appearance  of  resonance  phenomena  between  cardiovascular  rhythms, that probably favors the meditation practice.

Download the complete article, click here