Skeletal muscle metabolism during exercise in patients with chronic heart failure.
OBJECTIVE
To investigate the metabolic response of skeletal muscle to exercise in patients with chronic heart failure and determine its relation to central haemodynamic variables.


METHODS
University hospital in Sweden.


METHODS
16 patients in New York Heart Association class II-III and 10 healthy controls.


METHODS
Skeletal muscle biopsies were obtained from the quadriceps muscle at rest and at submaximal and maximal exercise. Right sided heart catheterisation was performed in eight patients.


RESULTS
The patients had lower maximal oxygen consumption than the control group (13.2 (2.9) v 26.8 (4.4) ml/kg/min, P < 0.001). They had reduced activities of citrate synthetase (P < 0.05) and 3-hydroxyacyl-CoA dehydrogenase (P < 0.05) compared with the controls. At maximal exercise adenosine triphosphate (P < 0.05), creatine phosphate (P < 0.01), and glycogen (P < 0.01) were higher whereas glucose (P < 0.001) and lactate (P < 0.06) were lower in the patients than in the controls. Citrate synthetase correlated inversely with skeletal muscle lactate at submaximal exercise (r = -0.90, P < 0.003). No correlations between haemodynamic variables and skeletal muscle glycogen, glycolytic intermediates, and adenosine nucleotides during exercise were found.


CONCLUSIONS
Neither skeletal muscle energy compounds nor lactate accumulation were limiting factors for exercise capacity in patients with chronic heart failure. The decreased activity of oxidative enzymes may have contributed to the earlier onset of anaerobic metabolism, but haemodynamic variables seemed to be of lesser importance for skeletal muscle metabolism during exercise.
Schaufelberger
M
M
Department of Medicine, Ostra University Hospital, Sweden.
Eriksson
B O
BO
Held
P
P
Swedberg
K
K
D000255:Adenosine Triphosphate / Q000378:metabolism; D000368:Aged; D006328:Cardiac Catheterization; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D005947:Glucose / Q000378:metabolism; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D006333:Heart Failure / Q000378:metabolism*; D006801:Humans; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000378:metabolism*; D010101:Oxygen Consumption; D010725:Phosphocreatine / Q000378:metabolism
D005958:Glucosephosphates; D007773:Lactates; D010725:Phosphocreatine; D019344:Lactic Acid; D019298:Glucose-6-Phosphate; D000255:Adenosine Triphosphate; D006003:Glycogen; D005947:Glucose