Effects of Slow Breathing Exercises on Cardiac Autonomic Functions in Anxiety Disorder—A Randomised Control Trial

Abstract

Background Anxiety disorders are commonly associated with a higher risk of fatal cardiovascular diseases (CVD). Anxiety disorders lead to dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, thus weakening the key neuronal components of the autonomic nervous system (ANS) that are involved in cardiovascular functions, leading to increased cardiovascular risk. Purpose Impaired ANS activity, as reduced parasympathetic tone is strongly associated with an increased risk of CVD in anxiety disorders. Slow pranayama influences the ANS by activating the parasympathetic tone and deactivating the sympathetic tone in healthy volunteers and various diseased conditions. Therefore, we aimed to study the effects of slow pranayama and savasana on cardiac autonomic function tests in anxiety disorder patients. Methods Anxiety disorder patients (N = 140) of either sex between the age group 18 and 40 years attending the psychiatry outpatient department (OPD) in JIPMER were recruited for the study and were randomly assigned into the pranayama group and control group. The Pranayama group practised slow pranayama and savasana for 8 weeks along with routine psychiatric care, while the control group continued with routine psychiatric care only. Outcome measures were heart rate variability (HRV), baroreflex sensitivity (BRS), 30:15 ratio during lying to standing, E: I ratio during deep breathing, and ∇DBP during isometric handgrip, which were assessed before and after the intervention period. Results After 8 weeks in the Pranayama group, the HRV parameters showed significant improvement towards the parasympathetic domain. Also, there was a significant increase in parasympathetic reactivity with a decrease in sympathetic reactivity and significant improvement in BRS. Conclusion Slow pranayama and savasana practice in anxiety disorder patients as an adjunct to routine psychiatric care effectively improves cardiac autonomic function with a shift towards parasympathetic predominance, with significant improvements in cardiovascular parameters. Slow pranayamas with savasana may be incorporated into the routine care of these patients to enhance their cardiovascular health.