Effects of motivation of the patient on indices of exercise capacity in chronic heart failure.

摘要: BACKGROUND--Measurement of variables metabolic gas exchange during exercise is widely used to assess the severity heart failure. The derived however, are potentially dependent on motivation patient and duration exercise. METHODS--The data from tests in 23 patients with exertional breathlessness were analysed derive following three common indices tolerance: anaerobic threshold, extrapolated maximum oxygen consumption, ventilation carbon dioxide production slope. reanalysed points first 90% subsequent exercise, 75%, finally up point where a respiratory ratio 1 was reached. RESULTS--The mean (SEM) threshold lower when computed than 100% (13.2 (1.0) ml/kg/min v 12.5 (1.0), p < 0.001) still 75% (11.4 (0.7), = 0.006 90%). Extrapolated consumption unchanged data, but higher (25.4 (2.1) at 28.6 0.001). slope became progressively shallower measured eventual exercise: 32.3 (1.5) 30.0 90%, 0.001; 28.3 0.001 90%. At 1, final calculation, (11.8 (0.9), 0.005) (27.5 (1.4), CONCLUSIONS--Anaerobic tends overestimate limitation tend underestimate severity. most reliable measures, independent effort provided that encouraged exceeds 1.