Involvement of autonomic nervous system in isometric handgrip in healthy young subject.

ABSTRACT

Background: HRV can be considered a relatively simple, noninvasive and sensitive method for studying autonomic modulation, purpose of the present study was to determine whether readily measured blood pressure (BP) indices and responses to autonomic reflex tests could be used as surrogates of short-term heart rate variability. Different Methods were used to evaluate sympathetic and Parasympathetic activity. Results: The autonomic function tests and heart rate variables were recorded and data was tabulated for Statistical evaluation. A two tailed P value less than or equal to 0.05 (5%) were considered statistically significant. Heart Rate Variability in Male Mean R-R interval and SDNN of time domain analysis were highly significant on comparing supine to standing (P<0.001),Similarly LF, HF power, Total Power and LFnu of frequency domain analysis were highly significant on comparing supine to standing (P<0.001) and in Females also it is same. Conclusion: Considering the results our data indicate a decrease in HRV that seems to be expressions of a reduction in autonomic modulation in postural change from supine to standing erect both in male and female subjects. The findings suggestive of a shift in cardiac autonomic regulation towards sympathetic activation in response to real life stressors which also includes the decrease in parasympathetic modulation and no significant correlation between readily measured blood pressure indices to heart rate variables in both male and female groups, we suggest that mean heart rate, SBP, DBP and RPP cannot be used as surrogates of HRV. However, observations need to be made in healthy subjects belonging to various age groups and in patients with conditions known to be associated with autonomic deregulation.