Statistical study of the fluctuations in the heart rhythm in subjects of different ages, in rest and with physiological stress

Abstract

Abstract. The human body is resilient but becomes frail when cardiac function is impaired, that is with sickness and age. Recently, it has been proposed to quantify frailty or resilience by a statistical study of time series [1]. One of the most studied physiological variables is heart rate variability (HRV), that has been associated to physiological frailty [2]. In this work, we carried out short cardiovascular monitoring (5 minutes) and studied the ANS response in the face of different stressors. Usually, HRV has been measured in rest conditions, in this way, spontaneous fluctuations are analized. For this contribution, we based on Ewing test and imposed two different kind of stressors: rhythmic breathing and standing upright. Several measures of HRV were analized. It was found that including stressors in this kind of measurements yields more information about adaptation to different environment (internal or external), also allowed to better distinguish different age groups (despite the fact that population was small). We found that heart rate response to standing and the modulation capacity decreases with age.