TO ASSESS AUTONOMIC ACTIVITY IN PATIENTS OF PRIMARY OPEN ANGLE GLAUCOMA (POAG) BY HEART RATE VARIABILITY (HRV) AND VALSALVA MANEUVER (VM) AND TO COMPARE WITH HEALTHY CONTROLS.
*Harminder Singh, Indu Khurana, C. S. Dhull.
ABSTRACT
Introduction POAG is known asâ€Å¾silent thief of vision‟ as it is asymptomatic disease progressing to blindness without exhibiting warning signs till advanced phase. Circulatory damage can occur on eye due to autonomic imbalance. HRV shows beat to beat fluctuation in heart rate. VM is used to assay integrity and stability of cardiac autonomic function depending on heart rate responses associated with arterial pressure stabilizing baroreflex mechanism. Material and method- Study was conducted Physiology department in collaboration with Ophthalmology department, PGIMS Rohtak. Study sample comprised of 30 POAG patients (group I) and 30 controls (group II). Basal HRV was assessed. HRV was recorded during after VM. Observation and results- Basal HRV showed significant (p 0.026) increase in LF(nu) in group I. During VM significant increase in SDNN (p < 0.05) in group I was observed. During valsalva recovery significant (p 0.035) decrease in NN50 was observed in group I than group II. Significant increase in LF(nu) [p 0.05], LF/HF ratio (p 0.048) and decrease in HF (nu) [p 0.013] was observed in group I. Discussion- HRV is regulated by constant involvement of sympathetic and parasympathetic system. Frequency domain variables of basal HRV showed reduced vagal tone and sympathetic predominance to heart in POAG patients. Significant increase in SDNN in group I depicted sluggish autonomic response during stress. POAG cases showed blunted response during strain showing delayed response to stress. Significant decrease in NN50 suggested incomplete recovery after stress. Conclusion- Basal HRV suggested decreased vagal tone and relatively sympathetic overdrive in POAG patients. VM suggested autonomic imbalance and inefficient compensatory mechanism during stress. During recovery persistently high sympathetic tone may be due to altered autonomic activity in POAG patients.
Keywords: Primary Open Angle Glaucoma, Heart rate variability, valsalva maneuver, valsalva recovery.
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