Metabolic abnormality of calf skeletal muscle is improved by localised muscle training without changes in blood flow in chronic heart failure.
OBJECTIVE
To investigate whether localised skeletal muscle training, which does not have a great influence on the heart, improves abnormalities of calf muscle metabolism in patients with chronic heart failure.


METHODS
Seven cardiac patients in New York Heart Association class II and III undertook a random order crossover trial. Training consisted of unilateral calf plantar flexion exercise. Before and after training, the patients' metabolic responses were examined during the calf exercise test with phosphorus-31 nuclear magnetic resonance spectroscopy (31P-MRS) and calf blood flow with plethysmography. The new Borg scale was employed as a subjective fatigue scale.


RESULTS
In a constant load exercise test (70% of maximum load achieved during the incremental exercise), standardised phosphocreatine and intracellular pH decreased less after training (p < 0.05, repeated measures analysis of variance). The new Borg scale improved significantly after training (p < 0.05). Blood flow did not change significantly in either test.


CONCLUSIONS
In patients with chronic heart failure, localised calf skeletal muscle training improved oxidative capacity without changes in calf blood flow. This training also improved the subjective fatigue scale. This training method may therefore alleviate leg fatigue experienced in daily activities.
Ohtsubo
M
M
Department of Cardiovascular Medicine, Hokkaido University School of Medicine, Sapporo, Japan. kitabata@med.hokudai.ac.jp
Yonezawa
K
K
Nishijima
H
H
Okita
K
K
Hanada
A
A
Kohya
T
T
Murakami
T
T
Kitabatake
A
A
D000368:Aged; D000704:Analysis of Variance; D018592:Cross-Over Studies; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006333:Heart Failure / Q000378:metabolism / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D007866:Leg / Q000098:blood supply; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply / Q000378:metabolism* / Q000503:physiopathology; D010725:Phosphocreatine / Q000378:metabolism; D010991:Plethysmography; D012039:Regional Blood Flow
D010725:Phosphocreatine