Yoshimura K.1,2, Yuguchi S.1, Urabe Y.2, Maeda N.2, Yoshida T.3
1Sakakibara Heart Institute of Okayama, Department of Rehabilitation, Okayama, Japan, 2Graduate School of Biomedical & Health Sciences, Hiroshima University, Department of Sports Rehabilitation, Hiroshima, Japan, 3Sakakibara Heart Institute of Okayama, Department of Cardiovascular Medicine, Okayama, Japan
Background: Heart failure (HF) is a common disease at present and approximately 26 million people worldwide are living with HF. Especially, the number of elderly patients with HF is predicted to gradually increase as the population ages. A cardiorespiratory steady state is normally obtained from the third minute of exercise in healthy individuals. On the other hand, in chronic HF patients, kinetics of oxygen uptake (V´O2) is delayed from the onset of the exercise compared to healthy subjects. The loss of muscle strength is one of the characteristics of HF and grip strength (GS) is an indicator of overall muscle strength and has relationship with exercise capacity. Additionally, weak GS was defined as 26 kilograms in men and 18 kilograms in women as a cut-point of sarcopenia in Asia from the Asian working group for sarcopenia (AWGS). However, kinetics of V´O2 during and after walking by difference of GS in patients with HF has not previously been evaluated.
Purpose: This study aimed to compare V´O2 during and after the six-minute walk between groups divided according to GS in patients with HF.
Methods: 26 patients who were over 65 years old and hospitalized for HF at our institution from April 2014 to October 2016 were included in this study. Patients consisted of 13 men and 13 women (mean age 77.0 ± 7.0 years, body mass index 21.6 ± 3.3 kg/m2, and LVEF 46.5 ± 18.9%). V´O2 was measured using the FitMate2000 (COSMED, Italy) at discharge period. Each subject walked along a 25-m, flat, obstacle-free corridor with chairs placed at both ends at self-selected speed for 6 min. Before and after the walk test, subjects sat on a chair for 3 min. GS was measured by using hand dynamometer (TOEI LIGHT, Japan). Subjects were divided into 2 groups by GS based on the cut-point of AWGS, the first group has higher GS (HF-H, n = 17), and second group has lower GS (HF-L, n = 9). The repeated measures ANOVA and Tukey method were used to compare V´O2 every 30sec from 30sec to 6 min during walk, and to compare V´O2 before walk as resting baseline with the value of every 30sec for 3 min after walk ended as time to recovery, in each group. The significance level was set at P 0.05.
Results: In HF-H, V´O2 stabilized from 2 min 30 sec and in HF-L from 3 min during walk (P 0.01). Regarding recovery of V´O2, in HF-H, V´O2 recovered after 2 min of walk test and in HF-L did not recover within 3 min after walk test (P 0.01).
Conclusion(s): In HF-L, a steady state and recovery of V´O2 were delayed in comparison with HF-H. The dynamics of V´O2, both during and after walking test have differences according to GS.
Implications: This study is a helpful indicator to evaluate the exercise strength with little load for elderly HF patients when physical therapists determine exercise prescription.
Funding acknowledgements: We have no funding acknowledgement in this study.
Topic: Cardiorespiratory
Ethics approval: All patients gave informed consent about the protocol, which was approved by the institutional ethics committee(the approval number 20140201).
All authors, affiliations and abstracts have been published as submitted.
