STUDY OF AUTONOMIC ACTIVITY IN PATIENTS WITH NORMAL TENSION GLAUCOMA (NTG) BY HEART RATE VARIABILITY (HRV) AND ISOMETRIC HANDGRIP TEST WITH HEALTHY CONTROLS
*Arijita Banerjee, Indu Khurana and C. S. Dhull
ABSTRACT
Introduction Some local changes have been documented suggesting Glaucoma is related to activity of
autonomic nervous system (ANS) but systemic association has not been established so far. The analysis of
Heart rate variability (HRV) is used to investigate sympatho-vagal imbalance within cardiovascular system.
Sustained handgrip is an important cardiac stress test to study the status of autonomic activity. Material and
method The study subjects carried out on 20 patients with Normal Tension Glaucoma of age group between 45-
65years of either sex (group ІІ) and 20 age & sex matched healthy controls (group І). Basal HRV and during
Handgrip testing was analysed by frequency domain method and the data was compiled and statistically
analysed using unpaired t test. Observation and results No statistical difference in baseline parameters of HRV
found in both groups. However, Low frequency variables LF(nu)( 58.94± 6.55), (p < 0.001) and LF/HF
ratio(2.3±0.37), (p < 0.000) were significantly increased on immediate release of handgrip in patients with NTG
as compared to controls [(LF 52.13±2.97),(LF/HF 1.47±0.29)] with a significant fall in high frequency variable
HF(nu) (26.11±4.27) in group ІІ (p < 0.000).During handgrip recovery there was a significant decrease in HF (nu)
(36.82±4.59), (p < 0.000) and raised LF/HF (1.28±0.13), (p-0.001) in group ІІ as compared to group І.
Conclusion In patients with NTG the observed findings suggested sympathetic hyperactivity in response to
stress (handgrip test) and reduced vagal activity during recovery period indicated of delayed recovery. These
observations indicate sympatho-vagal imbalance in Normal Tension Glaucoma. Therefore, identification of such
patients may be possible with the use of non-invasive technique i.e HRV.
Keywords: Heart rate variability, isometric handgrip, handgrip recovery.
[Full Text Article]
[Download Certificate]
Impact Factor : 8.181 
