Cohen-Solal A, Zannad F, Kayanakis J G, Gueret P, Aupetit J F, Kolsky H
Cardiology, CHU Bichat, Paris, France.
Eur Heart J. 1991 Oct;12(10):1055-63. doi: 10.1093/oxfordjournals.eurheartj.a059837.
Assessment of the ventilatory threshold (VT) has been proposed to assess exercise tolerance more objectively, particularly in clinical trials, but reproducibility, interobserver variability and feasibility of the graphical methods for determination of VT have not been properly studied in patients with chronic heart failure (CHF). Fifty-one patients with mild to moderate CHF (mean peak oxygen uptake (VO2): 20.5 ml.min-1.kg-1) were assessed during two consecutive bicycle exercise tests within 8 days. Two graded exercise protocols were compared with stages of 30 W every 3 min (22 patients) or 10 W/min (29 patients). VT was determined separately by five trained physicians using five different graphical methods. The 'crossing method' (first crossing of the VCO2 and VO2 curves) yielded the highest rate of determination (88%) but tended to overestimate the mean VT. The VE method (disproportionate increase of ventilation relative to VO2) produced the best interobserver agreement (coefficient of variation = 78%). Peak VO2 was very highly reproducible in both exercise protocols (relative difference 2-test 1/test 1 = -0.32% for the 30 W 3 min protocol; +2.18% for the 10 W.min-1 protocol). The reproducibility of VT was slightly lower regardless of the graphical method used to determine it (relative differences varied from -3.3% to +7.3%). Therefore, peak VO2 appears more suitable than VT for assessment of exercise tolerance in CHF.
有人提出评估通气阈值（VT）能更客观地评估运动耐力，尤其是在临床试验中，但对于慢性心力衰竭（CHF）患者，用于确定VT的图形方法的可重复性、观察者间变异性和可行性尚未得到充分研究。对51例轻度至中度CHF患者（平均峰值摄氧量（VO2）：20.5 ml·min⁻¹·kg⁻¹）在8天内连续进行两次自行车运动试验时进行了评估。比较了两种分级运动方案，一种是每3分钟增加30 W（22例患者），另一种是每分钟增加10 W（29例患者）。由五名训练有素的医生分别使用五种不同的图形方法来确定VT。“交叉法”（VCO2和VO2曲线的首次交叉）的确定率最高（88%），但往往高估了平均VT。VE法（通气相对于VO2的不成比例增加）产生了最佳的观察者间一致性（变异系数 = 78%）。在两种运动方案中，峰值VO2的重复性都非常高（对于30 W 3分钟方案，相对差异2检验1/检验1 = -0.32%；对于10 W·min⁻¹方案，为 +2.18%）。无论用于确定VT的图形方法如何，VT的可重复性都略低（相对差异从 -3.3% 到 +7.3% 不等）。因此，对于评估CHF患者的运动耐力，峰值VO2似乎比VT更合适。
