Heart Rate Variation In Normal Subjects Among Various Age Groups

HRV is negligible variation between the periods of successive sinus heart rate, reflects the status of function of cardial automatic nervous system. This kind of negligible variation between the heart rate can be record, measure and calculate by computer ECG Detection System and use as guides for Clinical application. It is well-known that HRV is the method about quantitative analysis of cardial automatic nervous system tension, frequency threshold analysis is one of the analysis methods have been given more attention these years, It is analysis the heart rate power spectrum of the speed and amplitude of heart rate variation, that is heart rate power spectrum analysis. In frequency domain analysis, HF refects the tension variation of vagus; LF reflects the tension variation of sympathetic nerve. It relates with outer blood vessel temperature regulation, rennin, angiotensin system and cardiac pumping function and so on; LF/HF can evaluate the proportionality between cardiac sympathetic nerve and vagus activity.The last two decades have witnessed the recognition of a significant relationship between the autonomic nervous system and cardiovascular mortality, including sudden cardiac death. Experimental evidence for an association between a propensity for lethal arrhythmias and signs of either increased sympathetic or reduced vagal activity has encouraged the development of quantitative markers of autonomic activity. Analysis of heart rate variation (HRV) has become a popular noninvasive tool for assessing the activities of the autonomic nervous system (ANS). HRV analysis is based on the concept that fast fluctuations may specifically reflect changes of sympathetic and vagal activity. It shows that the structure generating the signal is not simply linear, but also involves nonlinear contributions. In this paper the largest Lyapunov exponent of ECG signals for different age groups has been calculated. The results show that, with aging the heart rate variability decreases. In this work, the ranges of nonlinear parameters for four age group normal subjects are presented.