Associate Professor, MGM Medical College, Navi Mumbai
Online published on 24 September, 2014.
Heart rate variability (HRV) is an important measure of autonomic functioning, which provides powerful means of observing the interplay between the sympathetic and parasympathetic nervous systems. In normal women, there was found predominance of parasympathetic over sympathetic tone. The HRV response to postural change is a sensitive measure of the shift in autonomic balance from parasympathetic to sympathetic predominance that, when attenuated or absent, has been correlated with prevalent disease in patients.
The purpose of the present study was to systematically investigate the effect of change in posture on HRV parameters using frequency domain measures in young adult Indian females.
The study was conducted on fifty young adult females.
Height in centimetres (cms), body weight in kilograms (kgs), Pulse and BP was noted. HRV was recorded with the help of Anu photo rheograph by frequency domain method in three postures in a sequence: lying, sitting and standing.
SPSS 17.0, one way ANOVA and Tuckey's Post Hoc test were used to find out statistical significance of the results.
The values of the mean RR Interval and mean HF for females in lying, sitting and standing positions were 0.75 ± 0.13, 0.74 ± 0.11 and 0.66 ± 0.08 and 26.46 ± 16.59, 21.25 ± 8.21 and 14.89 ± 8.11 respectively. Both decreased significantly when posture changed from supine to sitting to standing.
The values of the mean LF for females in lying, sitting and standing positions were 20.20 ± 8.37, 31.11 ± 9.59 and 28.44 ± 12.19 respectively. It increased significantly when posture changed from supine to standing to sitting.
The values of the mean TP and mean VLF in three positions were not significantly different.
The decrease of mean RR interval and mean HFand an increase of mean LF with changes in posture shows that females have higher cardiac parasympathetic modulation and lesser sympathetic modulation which contributes as one of the cardio-protective mechanisms in them.
Heart Rate Variability, Posture Change, Autonomic Nervous System, Young Adult Females, Indian
