ANAEROBIC THRESHOLD IN PATIENTS WITH CHRONIC CARDIAC-FAILURE DUE TO ISCHEMIC-HEART-DISEASE

Objectives. Anaerobic threshold was measured to examine its relationsh ip with venous lactate levels and the reproducibility of gas exchange methods. Methods: Twenty patients with chronic cardiac failure due to ischaemic heart disease underwent two successive treadmill tests with measurements of respiratory gas exchange. Results: An anaerobic thresh old was demonstrated in 78 p. 100 of tests, by plotting either VE / VO 2 or VCO2 / VO2, and reproducibility between the two tests was satisfa ctory. Peripheral-venous lactate levels did not increase from rest to the end of the exercise stage prior to the anaerobic threshold, but di d increase significantly thereafter. Where an anaerobic threshold coul d be demonstrated, it was reproducible and correlated strongly with pe ak achieved VO2. Conclusion: However, as measurement of anaerobic thre shold requires exercise to 90 p. 100 maximum VO2, it may be preferable to continue until limiting symptoms, and use peak achieved VO2 as the end point. Anaerobic threshold is a reproducible measure of anaerobic exercise capacity.