Study of Heart Rate Variability in Control and Hypertensive Subjects

ABSTRACT

Autonomic nervous system comprising sympathetic and parasympathetic divisions has important role inregulating the cardiovascular system. Heart rate variability has been shown to give objective assessment ofautonomic function. Peripheral Pulse Analyzer has been used to study heart rate variability in controls andhypertensive subjects for understanding manifestations of hypertension on autonomic activity. Subjects havebeen divided in two age groups; 18-30 years and 31-44 years and variability parameters have been comparedwith respect to gender stratification, age stratification and disease stratification. Statistical analysis hasshown marked reduction in the coefficient of variation for variability parameter expressed as logarithm (to thebase 10) in comparison to raw or average value of the parameter and has yielded higher discriminatorystrength in various stratified groups. Excluding age and gender sensitive parameters, significant differenceis observed in amplitude of low frequency component for lower age group male/female hypertensives andamplitude as well as area of low frequency component for higher age group female hypertensives. Theseobservations are in agreement with similarly targeted previous studies. Higher age group male controls andhypertensives, however, could not be discriminated by variability study probably due to similar changesmanifested by senility and hypertension. Thus amplitude and area of low frequency component in heart ratevariability spectrum is identified as hypertension specific parameter.