Muscle Afferent Feedback Effects in Patients With Heart Failure
Muscle Afferent Feedback Effects in Patients With Heart Failure: The Development of Central Fatigue
研究概览
详细说明
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.
研究类型
注册 (实际的)
阶段
- 阶段1
联系人和位置
学习地点
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Utah
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Salt Lake City、Utah、美国、84148
- Veterans Affairs Salt Lake City Heath Care System
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Salt Lake City、Utah、美国、84148
- George E Wahlen Vetern Affairs Medical Center
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参与标准
资格标准
适合学习的年龄
接受健康志愿者
有资格学习的性别
描述
Heart Failure Inclusion Criteria:
- Subjects with a history of stable cardiomyopathy (ischemic and non-ischemic, greater than 1 year duration, ages 20-79 years)
- New York Heart Association class I through IV symptoms
- Left ventricular ejection fraction less than 35 percent (heart failure patients with reduced left ventricular ejection fraction) or greater than 50 percent (heart failure patients with preserved left ventricular ejection fraction)
- Sedentary, no regular physical activity for at least 6 months prior
- Post-menopausal for at least 2 years and follicle stimulating hormone greater than 40
Heart Failure Exclusion Criteria:
- Patients with atrial fibrillation or heart failure believed to be secondary to atrial fibrillation
- Morbidly obese patients with a body mass index greater than 35
- Patients with uncontrolled hypertension, greater than 160/100
- Anemia with a hemoglobin less than 9
- Severe renal insufficiency (creatinine clearance less than 30 by the Cockcroft-Gault formula)
- Patients with significant non-cardiac comorbidities
- Orthopedic limitations that would prohibit them from performing the elbow-flexor exercise
- Current smoker or smoking history of 15 packs or more per year
- Women currently taking hormone replacement therapy
Healthy Control Inclusion Criteria:
- Ages 20-75 years
- Sedentary, no regular physical activity for at least 6 months prior
- Post-menopausal for at least 2 years and follicle stimulating hormone greater than 40
Healthy Control Exclusion Criteria:
- History of cardiovascular related abnormalities or pulmonary abnormalities
- Morbidly obese patients with a body mass index greater than 35
- Patients with uncontrolled hypertension, greater than 160/100
- Anemia with a hemoglobin less than 9
- Orthopedic limitations that would prohibit them from performing the elbow-flexor exercise
- Current smoker or smoking history of 15 packs or more per year
- Women currently taking hormone replacement therapy
学习计划
研究是如何设计的？
设计细节
- 主要用途：基础科学
- 分配：非随机化
- 介入模型：并行分配
- 屏蔽：无（打开标签）
武器和干预
参与者组/臂 |
干预/治疗 |
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其他：Heart Failure Patients
Patients with heart failure will undergo intervention of muscle contraction with metabolite solution administration.
Maximal voluntary muscle contraction exercise with varying metabolite solution administration of adenosine triphosphate, lactate, and protons with phosphate buffer.
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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
其他名称：
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其他：Control Participants
Healthy control participants will undergo intervention of muscle contraction with metabolite solution administration.
Maximal voluntary muscle contraction exercise with varying metabolite solution administration of adenosine triphosphate, lactate, and protons with phosphate buffer.
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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
其他名称：
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研究衡量的是什么？
主要结果指标
结果测量 |
大体时间 |
|---|---|
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Elbow Flexor Maximal Voluntary Contraction in newton-meters
大体时间：2 minutes
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2 minutes
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合作者和调查者
调查人员
- 首席研究员：Markus Amann, PhD、University of Utah
研究记录日期
研究主要日期
学习开始
初级完成 (实际的)
研究完成 (实际的)
研究注册日期
首次提交
首先提交符合 QC 标准的
首次发布 (估计)
研究记录更新
最后更新发布 (实际的)
上次提交的符合 QC 标准的更新
最后验证
更多信息
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