A Comparative study of heart rate variability during Valsalva maneuver in healthy, hypertensive and hypertensive diabetic subjects

BackgroundHypertension and Diabetes are known to have autonomic dysfunction and indices of heart rate variability provide window to understand the autonomic modulation of cardio respiratory systems. HypothesisCo existing morbidity in Hypertensive diabetic group will cause enhancement of autonomic dysfunction. DesignHospital based case-control study. Hypertensive and Hypertensive diabetics (30 males each), not on regular medicines were selected from the Medicine and Diabetic OPD over a period of one year,and included in the study. Age and sex matched healthy controls were selected from hospital staff.Heart rate variability tests were done in the research laboratory of department of Physiology. Materials and methodsAfter proforma the basal heart rate and resting blood pressures were recorded for each subject. Valsalva maneuver and the ECG recording was done on Polyrite-D Machine for one minute. Valsalva ratio was calculated. Statistical analysisANOVA, Tuckeys, and Pearson co-relation coefficient tests were used to analyze the appropriate data. ResultsThe mean VR of hypertensive subjects was.1.2647 + 0.1608,statistically not significant when compared to healthy (1.3137 + 0.1714).The mean VR of hypertensive diabetics was 1.1883+ 0.1302,statistically highly significant. Key wordsvalsalva ratio,HRV,autonomic functions,frequency analysis