Dynamic hyperinflation is observed during exercise in 60% of patients with clinically stable pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH), intensifying exertional dyspnoea. The impact of dynamic changes in respiratory mechanics during exercise on qualitative dimensions of dyspnoea in these patients has not been evaluated. 26 patients (PAH n=17; CTEPH n=9) performed an incremental symptom-limited cycle exercise test. Minute ventilation (V′E), breathing pattern, operating lung volumes and dyspnoea intensity were assessed throughout exercise. Dyspnoea quality was serially assessed during exercise using a three-item questionnaire (dyspnoea descriptors). The inflection point of tidal volume (VT) relative to V′E was determined for each incremental test. Changes in inspiratory capacity during exercise defined two groups of patients: hyperinflators (65%) and non-hyperinflators (35%). Multidimensional characterisation of dyspnoea was performed after exercise using the Multidimensional Dyspnea Profile. In hyperinflators, inspiratory capacity decreased progressively throughout exercise by 0.36 L, while remaining stable in non-hyperinflators. The “work/effort” descriptor was most frequently selected throughout exercise in both types of patients (65% of all responses). At the VT/V′E inflection, work/effort plateaued while “unsatisfied inspiration” descriptors became selected predominantly only in hyperinflators (77% of all responses). In the affective domain, the emotion most frequently associated with dyspnoea was anxiety. In pulmonary hypertension patients who develop hyperinflation during exercise, dyspnoea descriptors referring to unsatisfied inspiration become predominant following the VT/V′E inflection. As these descriptors are generally associated with more negative emotional experiences, delaying or preventing the VT/V′E inflection may have important implications for symptom management in patients with pulmonary hypertension. The inflection in tidal volume relative to ventilation marks the onset of a large increase in dyspnoea intensity and in the selection frequency of unsatisfied inspiration as the predominant dyspnoea descriptor in patients with stable pulmonary hypertension http://bit.ly/2JRA5bI

中文翻译：

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稳定型肺动脉高压患者劳力性呼吸困难的强度和质量

60% 的临床稳定肺动脉高压 (PAH) 和慢性血栓栓塞性肺动脉高压 (CTEPH) 患者在运动期间观察到动态过度充气，从而加剧劳力性呼吸困难。尚未评估运动期间呼吸力学的动态变化对这些患者呼吸困难定性维度的影响。26 名患者（PAH n=17；CTEPH n=9）进行了增量症状限制循环运动测试。在整个运动过程中评估分钟通气量 (V'E)、呼吸模式、操作肺容积和呼吸困难强度。使用三项问卷（呼吸困难描述符）在运动期间连续评估呼吸困难质量。对于每个增量测试，确定潮气量 (VT) 相对于 V'E 的拐点。运动期间吸气量的变化定义了两组患者：过度充气者 (65%) 和非过度充气者 (35%)。运动后使用多维呼吸困难概况对呼吸困难进行多维表征。在过度充气机中，吸气能力在整个运动过程中逐渐降低 0.36 L，而在非充气机中保持稳定。“工作/努力”描述符在两种类型的患者的整个运动过程中最常被选择（占所有反应的 65%）。在 VT/V'E 拐点处，工作/努力趋于平稳，而“不满意的灵感”描述词仅在超级充气机中被选择（占所有响应的 77%）。在情感领域，最常与呼吸困难相关的情绪是焦虑。在运动期间发生过度充气的肺动脉高压患者中，在 VT/V'E 拐点之后，呼吸困难描述词指的是不满意的吸气变得占主导地位。由于这些描述词通常与更多的负面情绪体验相关，因此延迟或预防 VT/V'E 拐点可能对肺动脉高压患者的症状管理具有重要意义。潮气量相对于通气量的变化标志着呼吸困难强度和不满意吸气的选择频率开始大幅增加，作为稳定肺动脉高压患者的主要呼吸困难描述 http://bit.ly/2JRA5bI 延迟或预防 VT/V'E 拐点可能对肺动脉高压患者的症状管理具有重要意义。潮气量相对于通气量的变化标志着呼吸困难强度和不满意吸气的选择频率开始大幅增加，作为稳定肺动脉高压患者的主要呼吸困难描述 http://bit.ly/2JRA5bI 延迟或预防 VT/V'E 拐点可能对肺动脉高压患者的症状管理具有重要意义。潮气量相对于通气量的变化标志着呼吸困难强度和不满意吸气的选择频率开始大幅增加，作为稳定肺动脉高压患者的主要呼吸困难描述 http://bit.ly/2JRA5bI