Premature Fatigue in Veterans With Heart Failure: Neuronal Influences

Summary

A hallmark of patients with heart failure (HF) is premature fatigue which impairs their quality of life and depicts a major source of morbidity. Premature fatigue may be attributed to a) contraction-induced transient changes within muscles (i.e. peripheral fatigue) and/or b) failure of the central nervous system to 'drive' / activate locomotor muscles (i.e. central fatigue). Both determinants of fatigue can lead to a reduction in a muscle's force and power generating capacity and to a compromised ability to perform whole body activities (e.g. walking). Recent findings in health have documented that group III/IV afferent fibers from the working muscle play a critical role in the development of both components of fatigue. Specifically, group III/IV muscle afferents limit central motor drive (CMD) during exercise and thereby exaggerate the development of central fatigue. In contrast, muscle afferents optimize muscle O2 delivery through the precise regulation of circulation and ventilation during exercise and thereby attenuate the development of peripheral fatigue.

Timeline

Start

2015-07-01

Primary completion

2017-01-15

Completion

2017-01-15

Publications

• Results Ives SJ, Amann M, Venturelli M, Witman MA, Groot HJ, Wray DW, Morgan DE, Stehlik J, Richardson RS. The Mechanoreflex and Hemodynamic Response to Passive Leg Movement in Heart Failure. Med Sci Sports Exerc. 2016 Mar;48(3):368-76. doi: 10.1249/MSS.0000000000000782.
• Results Sidhu SK, Weavil JC, Venturelli M, Rossman MJ, Gmelch BS, Bledsoe AD, Richardson RS, Amann M. Aging alters muscle reflex control of autonomic cardiovascular responses to rhythmic contractions in humans. Am J Physiol Heart Circ Physiol. 2015 Nov;309(9):H1479-89. doi: 10.1152/ajpheart.00433.2015. Epub 2015 Sep 18.
• Results Weavil JC, Sidhu SK, Mangum TS, Richardson RS, Amann M. Fatigue diminishes motoneuronal excitability during cycling exercise. J Neurophysiol. 2016 Oct 1;116(4):1743-1751. doi: 10.1152/jn.00300.2016. Epub 2016 Jul 20.
• Results Amann M, Sidhu SK, Weavil JC, Mangum TS, Venturelli M. Autonomic responses to exercise: group III/IV muscle afferents and fatigue. Auton Neurosci. 2015 Mar;188:19-23. doi: 10.1016/j.autneu.2014.10.018. Epub 2014 Oct 23.
• Results Wray DW, Amann M, Richardson RS. Peripheral vascular function, oxygen delivery and utilization: the impact of oxidative stress in aging and heart failure with reduced ejection fraction. Heart Fail Rev. 2017 Mar;22(2):149-166. doi: 10.1007/s10741-016-9573-4.

Drugs

Indications