ABSTRACT
Skeletal muscle in heart failure
All body systems, including skeletal muscle,
are involved in the development of the heart
failure syndrome. Skeletal muscle dysfunction
comprises muscle fibre atrophy,1 shift in fibre
type to a higher proportion of anaerobic type
IIb fibres, impaired oxidative capacity at rest
and metaboreceptor dysfunction.4 The
metaboreceptors are sensitive to work
performed by skeletal muscle. In part they are
responsible for the ventilatory response to
exercise and are more active than usual in
patients with heart failure. Skeletal muscle has
Overall, impaired skeletal muscle function
contributes to exercise intolerance8 and is
The cause of the skeletal myopathy is not
clear. Physical deconditioning may contribute
to skeletal muscle dysfunction.10 Sympathetic
and cytokine activation are pathophysiological
processes that contribute to abnormal skeletal
muscle metabolism.11 There is a general
metabolic change in heart failure in favour of
catabolic over anabolic processes,12 including
insulin and growth hormone resistance, and
rise in the ratio of catabolic to anabolic
steroids. These changes might contribute to
muscle changes.
