Background: Hypertension is one of the most rampant diseases in the world. Many genes are responsible for expression of normal blood pressure. This hints a probable role of family history in the development of hypertension, which we are trying to assess in this study. As BP is regulated by autonomic nervous system (ANS), altered activity of ANS suggestsa greater risk of development of hypertension. ANS is assessed by HRV which is a simple and noninvasive test. HRV represents the total amount of fluctuations in heart rate and R-R interval measured by time domain and frequency domain methods. Deep breathing causes stimulation of parasympathetic system by activating the stretch receptors. Hence HRV during deep breathing gives an idea about the activity of parasympathetic nervous system. Materials & Methods: We studied 67 subjects with or without family history of hypertension. BP and HRV of the two groups were compared,during normal breathing and deep breathing. Results: Two groups did not show significant discrepancy in BP and HRV at rest. However, HRV by time domain analysis (RMSSD and pNN50) showed a lower value in study group compared to control group in which RMSSD values were significantly less during deep breathing. This indicates that although the recorded BP of offsprings of hypertensive parents show a normal value at rest, they are havinga distorted ANS activity which is not manifested at rest. The low parasympathetic activity present in them became evident by the autonomic excitatory maneuver i.e. deep breathing. Conclusion: From this study it is apparentthat the wards of hypertensive parents are more prone to develop hypertension.

Keywords: Blood Pressure; Deep Breathing; Heart Rate Variability.