Premature Fatigue in Veterans With Heart Failure: Neuronal Influences
Status:
Completed
Trial end date:
2017-01-15
Target enrollment:
Participant gender:
Summary
A hallmark of patients with heart failure (HF) is premature fatigue which impairs their
quality of life and depicts a major source of morbidity. Premature fatigue may be attributed
to a) contraction-induced transient changes within muscles (i.e. peripheral fatigue) and/or
b) failure of the central nervous system to 'drive' / activate locomotor muscles (i.e.
central fatigue). Both determinants of fatigue can lead to a reduction in a muscle's force
and power generating capacity and to a compromised ability to perform whole body activities
(e.g. walking). Recent findings in health have documented that group III/IV afferent fibers
from the working muscle play a critical role in the development of both components of
fatigue. Specifically, group III/IV muscle afferents limit central motor drive (CMD) during
exercise and thereby exaggerate the development of central fatigue. In contrast, muscle
afferents optimize muscle O2 delivery through the precise regulation of circulation and
ventilation during exercise and thereby attenuate the development of peripheral fatigue.