NCT01919918

Muscle Afferent Feedback Effects in Patients With Heart Failure

Muscle Afferent Feedback Effects in Patients With Heart Failure: The Development of Central Fatigue

• Status: Completed
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 144 (actual)
• Sponsor: University of Utah · Academic / Other
• Sex: All
• Age: 20 Years – 79 Years
• Healthy volunteers: Accepted

Summary

The purpose of the study is to find out more about the mechanism by which neural feedback from the working muscle affects the development of central fatigue during exercise. Subjects with chronic heart failure (HF) and healthy subject counterparts will be tested to determine the mechanisms accounting for the premature fatigue characterizing HF patients during physical activity.

Detailed description

A substantial part in limiting exercise and/or physical activity in humans results from the development of peripheral and central fatigue during physical activity. Peripheral fatigue comprises biochemical changes within the metabolic milieu of the working muscle leading to an attenuated response to neural excitation, while central fatigue comprises a failure of the central nervous system to drive motoneurons. Patients with HF have overactive group III/IV muscle afferents and an exaggerated development of central fatigue during physical activity that is not explained by their reduced physical conditioning or cardiac insufficiency caused by their failing heart. The exact mechanisms accounting for the exaggerated central fatigue in HF remains elusive, however, the development of central fatigue during exercise has recently been linked to signaling by group III/IV muscle afferents. This makes the heightened neural feedback in HF a likely candidate for these patients' increased susceptibility to central fatigue. Lower pH, increased lactate and increased adenosine triphosphate has been shown to activate group III/IV afferents in a physiological manner and thus induce, in a rested and unfatigued muscle, the intramuscular milieu associated with moderate to heavy exercise. The objective of this study is to quantitate and compare the sensitivity of group III/IV afferents and associated effects on central fatigue in HF patients and healthy controls when skeletal muscle is subject to controlled lower pH, increased lactate and increased adenosine triphosphate.

Conditions

• Chronic Heart Failure

Interventions

Type	Name	Description
DRUG	Muscle Contraction with Metabolite Solution Administration	Participants will perform maximal elbow flexor or knee extensor contractions before and after administration of metabolite solutions of pH 7.2, pH 7.0 and pH 6.6

Timeline

• Start date: 2013-09-01
• Primary completion: 2018-01-03
• Completion: 2018-01-03
• First posted: 2013-08-09
• Last updated: 2018-01-08

Locations

2 sites across 1 country: United States