Muscle Afferent Feedback Effects in Patients With Heart Failure
Muscle Afferent Feedback Effects in Patients With Heart Failure: The Development of Central Fatigue
調査の概要
詳細な説明
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.
研究の種類
入学 (実際)
段階
- フェーズ 1
連絡先と場所
研究場所
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Utah
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Salt Lake City、Utah、アメリカ、84148
- Veterans Affairs Salt Lake City Heath Care System
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Salt Lake City、Utah、アメリカ、84148
- George E Wahlen Vetern Affairs Medical Center
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参加基準
適格基準
就学可能な年齢
健康ボランティアの受け入れ
受講資格のある性別
説明
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
研究計画
研究はどのように設計されていますか？
デザインの詳細
- 主な目的：基礎科学
- 割り当て：非ランダム化
- 介入モデル：並列代入
- マスキング：なし（オープンラベル）
武器と介入
参加者グループ / アーム |
介入・治療 |
|---|---|
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他の：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
他の名前：
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他の：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
他の名前：
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この研究は何を測定していますか？
主要な結果の測定
結果測定 |
時間枠 |
|---|---|
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Elbow Flexor Maximal Voluntary Contraction in newton-meters
時間枠：2 minutes
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2 minutes
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協力者と研究者
スポンサー
捜査官
- 主任研究者：Markus Amann, PhD、University of Utah
研究記録日
主要日程の研究
研究開始
一次修了 (実際)
研究の完了 (実際)
試験登録日
最初に提出
QC基準を満たした最初の提出物
最初の投稿 (見積もり)
学習記録の更新
投稿された最後の更新 (実際)
QC基準を満たした最後の更新が送信されました
最終確認日
詳しくは
本研究に関する用語
追加の関連 MeSH 用語
その他の研究ID番号
- 62914
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