A novel cardiopulmonary exercise test protocol and criterion to determine maximal oxygen uptake in chronic heart failure

作者：Bowen T Scott; Cannon Daniel T; Begg Gordon; Baliga Vivek; Witte Klaus K; Rossiter Harry B^*

来源：Journal of Applied Physiology, 2012, 113(3): 451-458.

DOI：10.1152/japplphysiol.01416.2011

• exercise
• gas exchange
• peak oxygen uptake
• respiratory exchange ratio

Bowen TS, Cannon DT, Begg G, Baliga V, Witte KK, Rossiter HB. A novel cardiopulmonary exercise test protocol and criterion to determine maximal oxygen uptake in chronic heart failure. J Appl Physiol 113: 451-458, 2012. First published May 31, 2012; doi:10.1152/japplphysiol.01416.2011.-Cardiopulmonary exercise testing for peak oxygen uptake ((V) over dot(O2peak)) can evaluate prognosis in chronic heart failure (CHF) patients, with the peak respiratory exchange ratio (RERpeak) commonly used to confirm maximal effort and maximal oxygen uptake ((V) over dot(O2max)). We determined the precision of RERpeak in confirming (V) over dot(O2max), and whether a novel ramp-incremental (RI) step-exercise (SE) (RISE) test could better determine (V) over dot(O2max) in CHF. Male CHF patients (n = 24; NYHA class I-III) performed a symptom-limited RISE-95 cycle ergometer test in the format: RI (4-18 W/min; similar to 10 min); 5 min recovery (10 W); SE (95% peak RI work rate). Patients (n = 18) then performed RISE-95 tests using slow (3-8 W/min; similar to 15 min) and fast (10-30 W/min; similar to 6 min) ramp rates. Pulmonary gas exchange was measured breath-bybreath. (V) over dot(O2peak) was compared within patients by unpaired t-test of the highest 12 breaths during RI and SE phases to confirm (V) over dot(O2max) and its 95% confidence limits (CI95). RERpeak was significantly influenced by ramp rate (fast, medium, slow: 1.21 +/- 0.1 vs. 1.15 +/- 0.1 vs. 1.09 +/- 0.1; P = 0.001), unlike (V) over dot(O2peak) (mean n = 18; 14.4 +/- 2.6 ml.kg(-1).min(-1); P = 0.476). Group (V) over dot(O2peak) was similar between RI and SE (n = 24; 14.5 +/- 3.0 vs. 14.7 +/- 3.1 ml.kg(-1).min(-1); P = 0.407); however, within-subject comparisons confirmed (V) over dot(O2max) in only 14 of 24 patients (CI95 for (V) over dot(O2max) estimation averaged 1.4 +/- 0.8 ml.kg(-1).min(-1)). The RERpeak in CHF was significantly influenced by ramp rate, suggesting its use to determine maximal effort and (V) over dot(O2max) be abandoned. In contrast, the RISE-95 test had high precision for (V) over dot(O2max) confirmation with patient-specific CI95 (without secondary criteria), and showed that (V) over dot(O2max) is commonly underestimated in CHF. The RISE-95 test was well tolerated by CHF patients, supporting its use for (V) over dot(O2max) confirmation.

• 出版日期2012-8