alexa Skeletal muscle ergoreflex overactivity is not related to exercise ventilatory inefficiency in non-hypoxaemic patients with COPD.


Journal of Clinical & Experimental Cardiology

Author(s): Nakamoto FP, Neder JA, Maia J, Andrade MS, Silva AC

Abstract Share this page

Abstract Increased ventilatory response to the metabolic demand ("ventilatory inefficiency") is commonly found during dynamic exercise in patients with chronic obstructive pulmonary disease (COPD). However, the role of enhanced muscle ergoreflex activity on this phenomenon is yet unknown. Ten non-hypoxaemic patients with varying degrees of disease severity (median and range of post-bronchodilator FEV(1) = 37.5 (27 to 70\%) predicted) and 7 age- and gender-matched controls were studied. Subjects were submitted to wrist flexion tests to the limit of tolerance (Tlim) with and without post-exercise regional circulatory occlusion (PE-RCO) for 3 min. The muscle ergoreflex activity was quantified as the difference in ventilation between PE-RCO and control recovery periods corrected for the resting values (ergoreflex Delta). In addition, the area under the ventilatory curve in the recovery period was calculated in both conditions. We found that Tlim and the physiological stress associated with localized exercise did not differ between patients and controls. However, patients had increased ventilatory response to a given metabolic demand (VCO(2)), either at rest or during exercise (P < 0.05). There were no significant differences in ergoreflex Delta in patients and controls (-2.2 to 2.4 (0.2) vs. -0.6 to 1.8 (0.3) l/min, respectively). In addition, the area under the ventilatory curve in the recovery period did not differ between control and PE-RCO tests in patients and healthy subjects (P > 0.05). We conclude that increased muscle ergoreflex activity did not contribute to an excessive ventilatory response to exercise in patients with COPD-at least in non-hypoxaemic and non-cachetic subjects. This article was published in Eur J Appl Physiol and referenced in Journal of Clinical & Experimental Cardiology

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version