Cohen-Solal A, Czitrom D, Geneves M, Gourgon R
Service de Cardiologie, Hôpital Beaujon, Clichy, France.
Int J Cardiol. 1997 Jun 27;60(1):23-9. doi: 10.1016/s0167-5273(97)00059-4.
Peak oxygen uptake (VO2) is attained at peak exercise in normal subjects. Recently, it was shown that the kinetics of the VO2 increase during exercise is slowed in chronic heart failure (CHF). We hypothesized that this may delay maximal VO2 after the end of exercise. We studied 21 patients who attained their peak VO2 15 s or more after cessation of a graded bicycle exercise test with breath-by-breath gas analysis (group 1). They were compared with 21 age- and sex-matched CHF patients who did not do so (group 2) and 21 normal subjects (group 3). Peak VO2 occurred 30 +/- 10 s (15-45) after exercise and was 10 +/- 7% (3-31) higher than end-exercise VO2 (P < 0.001) in group 1. Group 1 patients had poorer functional status (NYHA class 3.0 +/- 0.2 vs. 2.4 +/- 0.5), a smaller ejection fraction (21 +/- 6 vs. 26 +/- 8%), a lower end-exercise VO2 (1156 +/- 251 vs. 1535 +/- 508 ml/min), a lower anaerobic threshold (762 +/- 183 vs. 970 +/- 265 ml/min), and an identical respiratory exchange ratio (1.09 +/- 0.13 vs. 1.06 +/- 0.12) relative to group 2 patients. The delta VO2/delta workrate ratio was lower (9.5 +/- 2.0 vs. 11.2 +/- 1.1 ml/W) and the half-time of VO2 recovery was longer (156 +/- 27 vs. 95 +/- 27 s) in group 1 than in group 2 (P < 0.05, P < 0.01 group 1 vs. group 2). Slow kinetics of the VO2 increase with exercise may delay achievement of peak VO2 beyond the maximal workrate achieved. Gas exchanges should thus be measured also during recovery so as not to underestimate the true peak VO2, especially in severe CHF patients referred for heart transplantation.
在正常受试者中，运动峰值时可达到最大摄氧量（VO₂）。最近有研究表明，慢性心力衰竭（CHF）患者运动过程中VO₂增加的动力学过程会减慢。我们推测这可能会导致运动结束后最大VO₂出现延迟。我们研究了21例患者，这些患者在进行分级自行车运动试验并通过逐次呼吸气体分析停止运动后15秒或更长时间达到了他们的最大VO₂（第1组）。将他们与21例年龄和性别匹配但未达到此标准的CHF患者（第2组）以及21例正常受试者（第3组）进行比较。第1组中，运动后30±10秒（15 - 45秒）出现最大VO₂，且比运动结束时的VO₂高10±7%（3 - 31%）（P < 0.001）。第1组患者的功能状态较差（纽约心脏协会分级为3.0±0.2 vs. 2.4±0.5），射血分数较小（21±6 vs. 26±8%），运动结束时的VO₂较低（1156±251 vs. 1535±508 ml/min），无氧阈值较低（762±183 vs. 970±265 ml/min），与第2组患者相比，呼吸交换率相同（1.09±0.13 vs. 1.06±0.12）。第1组的VO₂变化量/功率变化率比值较低（9.5±
