{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T13:11:32Z","timestamp":1787836292188,"version":"build-2784847793"},"reference-count":0,"publisher":"BMJ","issue":"2","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["Heart"],"published-print":{"date-parts":[[1997,2]]},"abstract":"<jats:p>OBJECTIVE: To assess the exercise limitation of patients with chronic heart failure (CHF) and its relation to possible pulmonary and ventilatory abnormalities. SETTING: A tertiary referral centre for cardiology. METHODS: The metabolic gas exchange responses to maximum incremental treadmill exercise were assessed in 55 patients with CHF (mean (SD) age 57.9 (13.0) years; 5 female, 50 male) and 24 controls (age 53.0 (11.1) years; 4 female, 20 male). Ventilatory response was calculated as the slope of the relation between ventilation and carbon dioxide production (VE\/VCO2 slope). RESULTS: Oxygen consumption (VO2) was the same at each stage in each group. Ventilation (VE) was higher in patients at each stage. Patients had a lower peak VO2 and a steeper VE\/VCO2 slope than controls. Dead space ventilation as a fraction of tidal volume (VD\/VT) was higher in patients at peak exercise, but dead space per breath was greater in controls at peak exercise (0.74 (0.29) v 0.57 (0.17) litres\/breath; P = 0.002). End tidal CO2 was lower in patients at all stages, and correlated with peak VO2 (r = 0.58, P &lt; 0.001). Alveolar oxygen tension was higher in patients at each stage than in controls. CONCLUSIONS: Patients with CHF have an increased ventilatory response at all stages of exercise. Although this is accompanied by an increase in VD\/VT, there is hyperventilation relative to blood gases. It is more likely that the excessive ventilation is not due to a primary pulmonary pathology, but rather, the increase in dead space is likely to be a response to increased ventilation.<\/jats:p>","DOI":"10.1136\/hrt.77.2.138","type":"journal-article","created":{"date-parts":[[2015,2,13]],"date-time":"2015-02-13T14:50:33Z","timestamp":1423839033000},"page":"138-146","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":67,"title":["The increased ventilatory response to exercise in chronic heart failure: relation to pulmonary pathology."],"prefix":"10.1136","volume":"77","author":[{"given":"A. L.","family":"Clark","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M.","family":"Volterrani","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J. W.","family":"Swan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"A. J.","family":"Coats","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[1997,2,1]]},"container-title":["Heart"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/hrt.77.2.138","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,9,20]],"date-time":"2025-09-20T07:28:42Z","timestamp":1758353322000},"score":1,"resource":{"primary":{"URL":"https:\/\/heart.bmj.com\/lookup\/doi\/10.1136\/hrt.77.2.138"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1997,2]]},"references-count":0,"journal-issue":{"issue":"2","published-online":{"date-parts":[[1997,2,1]]},"published-print":{"date-parts":[[1997,2]]}},"alternative-id":["10.1136\/hrt.77.2.138"],"URL":"https:\/\/doi.org\/10.1136\/hrt.77.2.138","relation":{},"ISSN":["1355-6037","1468-201X"],"issn-type":[{"value":"1355-6037","type":"print"},{"value":"1468-201X","type":"electronic"}],"subject":[],"published":{"date-parts":[[1997,2]]}}}