Effect of yoga as an add-on therapy in the modulation of heart rate variability in children with duchenne muscular dystrophy

Background: Duchene muscular dystrophy (DMD) is a progressive muscular disorder. Cardiac disorder is the second-most common cause of death in children with DMD, with 10%–20% of them dying of cardiac failure. Heart rate variability (HRV) is shown to be a predictor of cardio-autonomic function. Physiotherapy (PT) is advised for these children as a regular treatment for maintaining their functional status. The effect of yogic practices on the cardio-autonomic functions has been demonstrated in various neurological conditions and may prove beneficial in DMD. Materials and Methods: In this study, 124 patients with DMD were randomized to PT alone or PT with yoga intervention. Home-based PT and yoga were advised. Adherence was serially assessed at a follow-up interval of 3 months. Error-free, electrocardiogram was recorded in all patients at rest in the supine position. HRV parameters were computed in time and frequency domains. HRV was recorded at baseline and at an interval of 3 months up to 1 year. Repeated-measures ANOVA was used to analyze longitudinal follow-up and least significant difference for post hoc analysis and P < 0.05 was considered statistically significant. Results: In our study, with PT protocol, standard deviation of NN, root of square mean of successive NN, total power, low frequency, high-frequency normalized units (HFnu), and sympathovagal balance improved at varying time points and the improvement lasted up for 6–9 months, whereas PT and yoga protocol showed an improvement in HFnu during the last 3 months of the study period and all the other parameters were stable up to 1 year. Thus, it is evident that both the groups improved cardiac functions in DMD. However, no significant difference was noted in the changes observed between the groups. Conclusion: The intense PT and PT with yoga, particularly home-based program, is indeed beneficial as a therapeutic strategy in DMD children to maintain and/or to sustain HRV in DMD