Muscular performance in heart failure

Abstract

Background: Some of the major symptoms in patients with chronic heart failure are muscle weakness and fatigue. However, not much is known about muscle performance in these patients compared to healthy controls. Methods and Results: Activity level, gait speed, hand grip strength, muscle performance of the knee extensors and flexors along with the plantar and dorsal flexors of the foot were evaluated. Muscle biopsies from the lateral vastus lateralis were taken. Sixteen patients in New York Heart Association class II or III were tested and compared to 112 reference subjects. Compared to the reference subjects, there was a reduction in activity level, gait speed, isometric and isokinetic peak torque for knee extension at different velocities, hand grip strength, peak torque for plantar and dorsal flexion of the ankle and isometric and isokinetic endurance for the knee extension. Recovery was faster. There were small differences in fiber composition. 3-Hydroxy-acylCoA-dehydrogenase and citrate synthase were lower, and lactate dehydrogenase was increased. Conclusions: Muscle performance is affected in terms of both strength and endurance, which might affect performance in everyday activities. The more pronounced reduction in hand grip compared to the other muscles tested could be an indication of intrinsic abnormalities in the skeletal muscle.