Immediate Effect of Different Pranayam on Short Term Heart Rate Variability in Health Care Students - A Preliminary Study

Introduction: Yoga produces consistent physiological changes and have sound scientific basis. Heart rate variability (HRV) has come to be widely used as a non-invasive tool to assess autonomic function in physiological as well as disease states. In view of this, the present study was aimed to study the effect of suryanadi(SNP) and chandranadi pranayams(CNP) on HRV in healthy young volunteers.

Methodology: 11male volunteers aged between 20-30yrs were assigned to a sequence randomly. Each volunteer was taught both SNP and CNP by trained yoga teacher and made to practice under direct supervision between 4-6.30 pm in ACYTER lab, JIPMER. HRV was recorded by using BIOHARNESS AcqKnowledge 4.1 version and analyzed by Kubios HRV 2.00 software. Basal resting parameters and HRV were recorded for 5 minutes after that SNP was performed in six cycles per minute for 5 minutes followed by 5 min rest. Three such sessions (before, during and after) HRV were recorded. The same procedure and recording ware followed for CNP.

Results: The time domain analysis of SNP revealed an increased heart rate with a decreased RMSSD, However the SDNN was increased. Frequency domain analysis, increased LF power and decreased HF power and LF/HF ratio increased after the intervention. In CNP, the time domain analysis, showed decreased heart rate and an increased pNN50. The frequency domain analysis revealed an increased HF power with decreased LF/HF ratio.

Discussion: SNP increase the sympathetic activity and CNP increases the parasympathetic activity and these can be appropriately advocated in many chronic cardiovascular diseases where the autonomic imbalance is one of the primary derangements.