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Muscle Afferent Feedback Effects in Patients With Heart Failure

4 de enero de 2018 actualizado por: Markus Amann, University of Utah

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

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.

Descripción general del estudio

Descripción detallada

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.

Tipo de estudio

Intervencionista

Inscripción (Actual)

144

Fase

  • Fase 1

Contactos y Ubicaciones

Esta sección proporciona los datos de contacto de quienes realizan el estudio e información sobre dónde se lleva a cabo este estudio.

Ubicaciones de estudio

    • Utah
      • Salt Lake City, Utah, Estados Unidos, 84148
        • Veterans Affairs Salt Lake City Heath Care System
      • Salt Lake City, Utah, Estados Unidos, 84148
        • George E Wahlen Vetern Affairs Medical Center

Criterios de participación

Los investigadores buscan personas que se ajusten a una determinada descripción, denominada criterio de elegibilidad. Algunos ejemplos de estos criterios son el estado de salud general de una persona o tratamientos previos.

Criterio de elegibilidad

Edades elegibles para estudiar

20 años a 79 años (Adulto, Adulto Mayor)

Acepta Voluntarios Saludables

Géneros elegibles para el estudio

Todos

Descripción

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

Plan de estudios

Esta sección proporciona detalles del plan de estudio, incluido cómo está diseñado el estudio y qué mide el estudio.

¿Cómo está diseñado el estudio?

Detalles de diseño

  • Propósito principal: Ciencia básica
  • Asignación: No aleatorizado
  • Modelo Intervencionista: Asignación paralela
  • Enmascaramiento: Ninguno (etiqueta abierta)

Armas e Intervenciones

Grupo de participantes/brazo
Intervención / Tratamiento
Otro: 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.
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
Otros nombres:
  • adenosine triphosphate, lactate, and protons with phosphate buffer
Otro: 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.
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
Otros nombres:
  • adenosine triphosphate, lactate, and protons with phosphate buffer

¿Qué mide el estudio?

Medidas de resultado primarias

Medida de resultado
Periodo de tiempo
Elbow Flexor Maximal Voluntary Contraction in newton-meters
Periodo de tiempo: 2 minutes
2 minutes

Colaboradores e Investigadores

Aquí es donde encontrará personas y organizaciones involucradas en este estudio.

Patrocinador

Investigadores

  • Investigador principal: Markus Amann, PhD, University of Utah

Fechas de registro del estudio

Estas fechas rastrean el progreso del registro del estudio y los envíos de resultados resumidos a ClinicalTrials.gov. Los registros del estudio y los resultados informados son revisados ​​por la Biblioteca Nacional de Medicina (NLM) para asegurarse de que cumplan con los estándares de control de calidad específicos antes de publicarlos en el sitio web público.

Fechas importantes del estudio

Inicio del estudio

1 de septiembre de 2013

Finalización primaria (Actual)

3 de enero de 2018

Finalización del estudio (Actual)

3 de enero de 2018

Fechas de registro del estudio

Enviado por primera vez

29 de julio de 2013

Primero enviado que cumplió con los criterios de control de calidad

6 de agosto de 2013

Publicado por primera vez (Estimar)

9 de agosto de 2013

Actualizaciones de registros de estudio

Última actualización publicada (Actual)

8 de enero de 2018

Última actualización enviada que cumplió con los criterios de control de calidad

4 de enero de 2018

Última verificación

1 de enero de 2018

Más información

Esta información se obtuvo directamente del sitio web clinicaltrials.gov sin cambios. Si tiene alguna solicitud para cambiar, eliminar o actualizar los detalles de su estudio, comuníquese con register@clinicaltrials.gov. Tan pronto como se implemente un cambio en clinicaltrials.gov, también se actualizará automáticamente en nuestro sitio web. .

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