title: Is the soleus a sentinel muscle for impaired aerobic capacity in heart failure?
abstract: OBJECTIVE
  Skeletal muscle wasting is well documented in chronic heart failure (CHF). This article provides a more detailed understanding of the morphology behind this muscle wasting and the relation between muscle morphology, strength, and exercise capacity in CHF. We investigated the effect of CHF on lower limb lean mass, detailed muscle-tendon architecture of the individual triceps surae muscles (soleus (SOL), medial gastrocnemius, and lateral gastrocnemius) and how these parameters relate to exercise capacity and strength.
  
  
  METHODS
  Eleven patients with CHF and 15 age-matched controls were recruited. Lower limb lean mass was assessed by dual energy x-ray absorptiometry and the architecture of skeletal muscle and tendon properties by ultrasound. Plantarflexor strength was assessed by dynamometry.
  
  
  RESULTS
  Patients with CHF exhibited approximately 25% lower combined triceps surae volume and physiological cross-sectional area (PCSA) compared with those of control subjects (P < 0.05), driven in large part by reductions in the SOL. Only the SOL volume and the SOL and medial gastrocnemius physiological cross-sectional area were statistically different between groups after normalizing to lean body mass and body surface area, respectively. Total lower limb lean mass did not differ between CHF and control subjects, further highlighting the SOL specificity of muscle wasting in CHF. Moreover, the volume of the SOL and plantarflexor strength correlated strongly with peak oxygen uptake (V˙O2peak) in patients with CHF.
  
  
  CONCLUSIONS
  These findings suggest that the SOL may be a sentinel skeletal muscle in CHF and provide a rationale for including plantarflexor muscle training in CHF care.
authors.affiliation: 1School of Sport Science, Exercise and Health, University of Western Australia, Crawley, Western Australia, AUSTRALIA; 2Advanced Heart Failure and Cardiac Transplant Service, Royal Perth Hospital, Perth, Western Australia, AUSTRALIA; 3School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, AUSTRALIA; 4School of Human Movement Studies, University of Queensland, St. Lucia Campus, Queensland, AUSTRALIA; 5Envision Medical Imaging, Perth, Western Australia, AUSTRALIA; 6Centre for Musculoskeletal Research, Griffith Health Institute, Griffith University, Gold Coast, Queensland, AUSTRALIA; and 7Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool, UNITED KINGDOM.
authors.forename: Fausto A
authors.initials: FA
authors.lastname: Panizzolo
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Maiorana
authors.forename: Louise H
authors.initials: LH
authors.lastname: Naylor
authors.forename: Glen A
authors.initials: GA
authors.lastname: Lichtwark
authors.forename: Lawrence
authors.initials: L
authors.lastname: Dembo
authors.forename: David G
authors.initials: DG
authors.lastname: Lloyd
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Green
authors.forename: Jonas
authors.initials: J
authors.lastname: Rubenson
mesh_terms: D000368:Aged; D001823:Body Composition; D018450:Disease Progression; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006333:Heart Failure / Q000473:pathology* / Q000503:physiopathology*; D006801:Humans; D007866:Leg / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000473:pathology* / Q000503:physiopathology*; D009133:Muscular Atrophy / Q000473:pathology* / Q000503:physiopathology*; D010101:Oxygen Consumption; D013710:Tendons / Q000473:pathology