Cardiac autonomic modulation in non-frail, pre-frail and frail elderly women: a pilot study

Frailty has been defined as a geriatric syndrome that results in high vulnerability to health adverse outcomes. This increased vulnerability state results from dysregulation of multiple physiological systems and its complex interactions. Thus, assessment of physiological systems integrity and of its dynamic interactions seems to be useful in the context of frailty management. Heart rate variability (HRV) analysis provides information about autonomic nervous system (ANS) function, which is responsible to control several physiologic functions. This study investigated the cardiac autonomic modulation by HRV analysis in community-dwelling elderly women classified as non-frail, pre-frail and frail. Twenty-three elderly women were assigned to the following groups: non-frail (n = 8), pre-frail (n = 8) and frail (n = 7). HRV assessment was performed through linear and non-linear analysis of cardiac interval variability. It was observed a higher sympathetic and lower parasympathetic modulation in frail when compared with non-frail and pre-frail groups (p < 0.05) as indicated by frequency domain indices. Additionally, frail group had a decreased 2LV % pattern (that reflects parasympathetic modulation) in the symbolic analysis in comparison with non-frail group. These findings suggest that frail elderly women present an autonomic imbalance characterized by a shift towards sympathetic predominance. Thus, monitoring ANS function in the context of frailty management may be an important strategy to prevention, diagnosis and treatment of this syndrome and its consequences.