Effect of head down tilt on heart rate variability

CONTEXT: Sirshasan is supposed to increase blood flow to the brain and considered to be beneficial for intellectual function, however mastering these techniques may be difficult. AIMS: To see the effect of headstand using a tilt table on heart rate variability (HRV). SETTINGS AND DESIGN: A cross-sectional study that was done on 26 healthy volunteers. METHODS AND MATERIAL: HRV was assessed in the supine position and 30° head tilt position for 5 min. HRV recording was done on the power lab (AD Instruments P Ltd, Castle Hill Australia). The tilt table used was Medica Podium, New Delhi, HLT-200. STATISTICAL ANALYSIS USED: Paired t-test. RESULTS: All the HRV parameters showed non-significant change except low-frequency parameters which showed significant change during head tilt. CONCLUSIONS: Headstand to a 30° using tilt table cause a decrease in the autonomic activity which is mainly because of decrease in sympathetic activity.