title: Beneficial effects of chronic low-frequency stimulation of thigh muscles in patients with advanced chronic heart failure.
abstract: OBJECTIVE
  Patients with chronic heart failure (CHF) exhibit detrimental changes in skeletal muscle that contribute to their impaired physical performance. This study investigates the possibility of counteracting these changes by chronic low-frequency electrical stimulation (CLFS) of left and right thigh muscles.
  
  
  RESULTS
  (mean+/-SD) 32 CHF patients (53+/-10 years) with an LVEF of 22+/-5%, NYHA II-IV, undergoing optimized drug therapy, were randomized in a CLFS group (CLFSG) or a control group (controls). The groups differed in terms of the intensity of stimulation, which elicited strong muscle contractions only in the CLFSG, whereas the controls received current input up to the sensory threshold without muscle contractions. Functional capacity was assessed by peak VO(2), work capacity, and a 6-min-walk (6-MW). Muscle biopsies were analyzed for myosin heavy chain (MHC) isoforms, citrate synthase (CS) and glyceraldehydephosphate dehydrogenase (GAPDH) activities. Peak VO(2)(mlmin(-1)kg -1) increased from 9.6+/-3.5 to 11.6+/-2.8 (P<0.001) in the CLFSG, and decreased from 10.6+/-2.8 to 9.4+/-3.2 (P<0.05) in the controls. The increase in the CLFSG was paralleled by increases in maximal workload (P<0.05) and oxygen uptake at the anaerobic threshold (P<0.01). The corresponding values of the controls were unchanged, as also the 6-MW values, the MHC isoform distribution, and both CS and GAPDH activities. In the CLFSG, the 6-MW values increased (P<0.001), CS activity was elevated (P<0.05), GAPDH activity decreased (P<0.01), and the MHC isoforms were shifted in the slow direction with increases in MHCI at the expense of MHCIId/x (P<0.01).
  
  
  CONCLUSIONS
  Our results suggest that CLFS is a suitable treatment to counteract detrimental changes in skeletal muscle and to increase exercise capacity in patients with severe CHF.
authors.affiliation: Department of Physical Medicine and Rehabilitation, General Hospital Vienna, University of Vienna, Vienna, Austria.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Nuhr
authors.forename: Dirk
authors.initials: D
authors.lastname: Pette
authors.forename: Rudolf
authors.initials: R
authors.lastname: Berger
authors.forename: Michael
authors.initials: M
authors.lastname: Quittan
authors.forename: Richard
authors.initials: R
authors.lastname: Crevenna
authors.forename: Martin
authors.initials: M
authors.lastname: Huelsman
authors.forename: Guenther F
authors.initials: GF
authors.lastname: Wiesinger
authors.forename: Petra
authors.initials: P
authors.lastname: Moser
authors.forename: Veronika
authors.initials: V
authors.lastname: Fialka-Moser
authors.forename: Richard
authors.initials: R
authors.lastname: Pacher
mesh_terms: D004599:Electric Stimulation Therapy / Q000379:methods*; D017079:Exercise Tolerance; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000503:physiopathology / Q000534:rehabilitation*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal; D018995:Myosin Heavy Chains / Q000097:blood; D011446:Prospective Studies; D011788:Quality of Life; D013848:Thigh
chemical_list: D018995:Myosin Heavy Chains