The physiology and pathophysiology of exercise hyperpnea
Jerome A Dempsey1, J Alberto Neder2, Devin B Phillips2
1John Rankin Laboratory of Pulmonary Medicine, Department of Population Health Sciences, University of Wisconsin-Madison, Madison, WI, United States.
Handbook of Clinical Neurology
|August 14, 2022
Summary
Exercise hyperpnea in health involves central command, muscle feedback, and CO2 exchange. In COPD, factors like dead space and lung mechanics impair breathing, causing dyspnea during exercise.
Area of Science:
- Physiology
- Respiratory Medicine
- Exercise Science
Background:
- Exercise hyperpnea in healthy individuals is driven by central command, muscle afferents, and CO2 exchange (V̇CO2).
- The relative contribution of these stimuli and the sensing mechanisms for V̇CO2 remain unclear.
- In COPD patients, abnormal ventilatory responses during exercise are linked to high dead space, increased neural drive, muscle fatigue, and mechanical constraints.
Purpose of the Study:
- To investigate the control of exercise hyperpnea in health and COPD.
- To elucidate the mechanisms behind abnormal ventilatory responses and dyspnea during exercise in COPD patients.
Main Methods:
- Analysis of diaphragm EMG amplitude and its relation to ventilatory output in COPD patients.
- Examination of feedforward and feedback stimuli during exercise in health and disease.
Main Results:
- Exercise hyperpnea in health is multifactorial, involving central and peripheral inputs.
- COPD patients exhibit exercise limitation due to factors including high dead space, excessive neural drive, and mechanical constraints.
Conclusions:
- Understanding the interplay of metabolic signals and respiratory control is crucial for both healthy individuals and those with COPD.
- Further research is needed to fully unravel the link between metabolism and breathing control in health and disease states.
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