Medical Research Center, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Department of Cardiology, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Am J Cardiol. 2023 Oct 1;204:207-214. doi: 10.1016/j.amjcard.2023.07.056. Epub 2023 Aug 7.
Because the 6-minute walking test (6MWT) is a self-paced submaximal test, the 6-minute walking distance (6MWD) is substantially influenced by individual effort level and physical condition, which is difficult to quantify. We aimed to explore the optimal indicator reflecting the perceived effort level during 6MWT. We prospectively enrolled 76 patients with pulmonary arterial hypertension and 152 healthy participants; they performed 2 6MWTs at 2 different speeds: (1) at leisurely speed, as performed in daily life without extra effort (leisure 6MWT) and (2) an increased walking speed, walking as the guideline indicated (standard 6MWT). The factors associated with 6MWD during standard 6MWT were investigated using a multiple linear regression analysis. The heart rate (HR) and Borg score increased and oxygen saturation (SO) decreased after walking in 2 6MWTs in both groups (all p <0.001). The ratio of difference in HR before and after each test (ΔHR) to HR before walking (HR) and the difference in SpO (ΔSpO) and Borg (ΔBorg) before and after each test were all significantly higher in both groups after standard 6MWT than after leisure 6MWT (all p <0.001). Multiple linear regression analysis revealed that ΔHR/HR was an independent predictor of 6MWD during standard 6MWT in both groups (both p <0.001, adjusted R = 0.737 and 0.49, respectively). 6MWD and ΔHR/HR were significantly lower in patients than in healthy participants (both p <0.001) and in patients with cardiac functional class III than in patients with class I/II (both p <0.001). In conclusion, ΔHR/HR is a good reflector of combined physical and effort factors. HR response should be incorporated into 6MWD to better assess a participant's exercise capacity.
因为 6 分钟步行试验（6MWT）是一种自我调节的亚最大强度试验，所以 6 分钟步行距离（6MWD）在很大程度上受到个体努力程度和身体状况的影响，这很难量化。我们旨在探索反映 6MWT 中感知努力程度的最佳指标。我们前瞻性地招募了 76 名肺动脉高压患者和 152 名健康参与者；他们以两种不同的速度进行了 2 次 6MWT：（1）以悠闲的速度进行，即日常生活中不额外用力（悠闲 6MWT），（2）按照指南增加步行速度（标准 6MWT）。使用多元线性回归分析研究了标准 6MWT 期间与 6MWD 相关的因素。在两组中，在两种 6MWT 后，心率（HR）和 Borg 评分增加，氧饱和度（SO）降低（均 p <0.001）。在两组中，与悠闲 6MWT 相比，标准 6MWT 后 HR 前后差值与 HR 比值（ΔHR）和 SpO 前后差值（ΔSpO）和 Borg 前后差值（ΔBorg）均显著升高（均 p <0.001）。多元线性回归分析显示，在两组中，ΔHR/HR 是标准 6MWT 期间 6MWD 的独立预测因子（均 p <0.001，调整后的 R 分别为 0.737 和 0.49）。6MWD 和 ΔHR/HR 在患者中均显著低于健康参与者（均 p <0.001），在心脏功能分级 III 患者中显著低于 I/II 级患者（均 p <0.001）。总之，ΔHR/HR 是体力和努力因素的良好反映。应将 HR 反应纳入 6MWD 中，以更好地评估参与者的运动能力。
