Six-minute walk test and frailty syndrome: effects on modulation autonomic of heart rate

• Grant number: 14/24163-9
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): June 01, 2015
• Effective date (End): February 29, 2016
• Field of knowledge: Health Sciences - Physiotherapy and Occupational Therapy
• Acordo de Cooperação: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal Investigator: Anielle Cristhine de Medeiros Takahashi
• Grantee: Ana Claudia Silva Farche
• Host Institution: Centro de Ciências Biológicas e da Saúde (CCBS). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

The frailty syndrome is described as a clinical state of vulnerability to stress and it is related to adverse outcomes such as hospitalizations, falls, and death. This geriatric syndrome is a consequence of the decline of the resilience and physiological reserves and it is associated with reduced complexity in physiological systems. In this scenario, the analysis of Heart Rate Variability (HRV) is an important tool to assess not only the integrity of SNA and their settings to different stimulus, but also the physiological complexity in HR regulation. Once the frailty syndrome carry functional implications and the fact that the exercise be considered as a key in treating of this syndrome, it is important to evaluate exercise submaximal capacity of this population in a functional exercise as the six minutes walk test (6MWT). Thus, the main objective of this study is to evaluate the complexity of HR at rest and against the stimulus of the six-minute walk test as well as during the recovery period. For this, elderly 42 that will be evaluated equally divided into three groups according to the phenotype of frailty proposed by Fried et al. al. (2001): Frail (F), Pre-Frail (PF) and Non-Frail (NF). Volunteers will participate anamnesis, laboratory tests and electrocardiogram at rest. The iRR will be collected by the heart rate monitor (Polar ® S810i) at rest (supine position for 10' followed by orthostatic position for 10'), during the 6MWT and the recovery period in the same sequence of initial rest. For data analysis, stationary excerpt 256 iRR will be selected in each condition. The complexity will be evaluated by conditional entropy. Additionally will be evaluated linear indices (variance and spectral components) and nonlinear (symbolic analysis). To check the effect of group, condition and the interaction between the same two-way ANOVA with repeated measures will be used, with post hoc Holm Sidak. The significance level for the tests is 5%. (AU)