Changes in heart rate variability following yogic visual concentration (Trataka)

Background: The yogic visual concentration technique, trataka is similar to meditation. Research studies have shown a shift toward the vagal tone during meditation. However, autonomic changes in trataka were not studied. Objectives: The present study was planned to assess the changes in heart rate variability (HRV) following trataka. Materials and Methods: HRV and breath rate were assessed in thirty healthy male volunteers with ages ranging from 20 to 33 years (group mean age ± SD, 23.8 ± 3.5) before and after yogic visual concentration (trataka) and control session on 2 separate days. Repeated measures analysis of variance (ANOVA) were performed with two "within subjects" factors, i.e., Factor 1: Sessions; trataka and control and Factor 2: States; "Pre", and "Post". This was followed by post-hoc analyses with Bonferroni adjustment comparing "Post" with "Pre" values. Results: There was a significant decrease in LF (RM ANOVA with Bonferroni adjustment P < 0.01) and increase in high frequency (P < 0.01) after trataka. Breath rate (P < 0.001) and heart rate (P < 0.01) were significantly reduced after trataka compared to before. Control session showed no change. Conclusions: The practice of trataka leads to increased vagal tone and reduced sympathetic arousal. Though trataka is known as cleansing technique, it could induce calm state of mind which is similar to a mental state reached by the practice of meditation