Background- Heart failure with preserved ejection fraction (HFpEF) patients experience symptoms of exertional dyspnea which may be related to lung fluid accumulation during exercise. A CT-based method was used to measure exercise-induced changes in extravascular lung fluid content and thoracic blood volumes and determine the effect of lung fluid on lung diffusing capacity for carbon monoxide (DL_CO) in stable HFpEF subjects and healthy controls. Methods- Nine subjects with HFpEF (Age 68±8y, BMI 32.1±2.6kg/m²) and eight healthy controls (62±9y, 23.8±2.4kg/m²) performed triplicate re-breathe DL_CO/DL­_NO tests in a supine position at rest and duplicate measurements during two 5 min submaximal exercise stages (15 and 35W) and recovery. Subjects subsequently performed a 5 min exercise bout (35W) inside a CT scanner, and extravascular lung fluid content and thoracic blood volumes were quantified at rest and immediately following exercise from thoracic and contrast perfusion scans, respectively. Results-Subjects with HFpEF had a higher lung fluid content at rest compared to controls (Mean±SD, HFpEF: 14.4±1.7%, Control: 12.8±1.7%, p=0.043) and a higher lung fluid content following exercise (15.2±2.0% vs. 12.6±1.5%, p=0.009). Higher lung fluid content was associated with a lower DL_CO and alveolar-capillary membrane conductance (Dm) in subjects with HFpEF (DL_CO: R=-0.57, p=0.022, Dm: R=-0.61, p=0.012), but not in controls. Pulmonary blood volume was not altered by exercise and was similar between groups. Conclusions-Submaximal exercise elicited a greater accumulation of lung fluid in HFpEF compared to controls, and lung fluid content was negatively correlated with lung diffusing capacity and alveolar-capillary membrane conductance in HFpEF.

中文翻译：

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运动对射血分数保留的心力衰竭患者胸腔血容量、肺积液和肺扩散能力的影响。

背景 - 射血分数保留的心力衰竭 (HFpEF) 患者会出现劳力性呼吸困难的症状，这可能与运动期间肺积液有关。使用基于 CT 的方法来测量运动引起的血管外肺液含量和胸腔血容量的变化，并确定肺液对稳定 HFpEF 受试者和健康对照的肺一氧化碳扩散能力 (DL _CO ) 的影响。方法-九受试者HFPEF（年龄68±8Y，BMI 32.1±2.6公斤/米²）和8名健康对照（62±9Y，23.8±2.4公斤/米²）上进行一式三份重新呼吸DL _CO / DL- _NO在休息时仰卧位进行测试，并在两个 5 分钟次极量运动阶段（15 和 35 瓦）和恢复期间重复测量。受试者随后在 CT 扫描仪内进行了 5 分钟的运动 (35W)，并分别通过胸腔和造影剂灌注扫描对静息和运动后的血管外肺液含量和胸腔血容量进行量化。结果 - 与对照组相比，HFpEF 受试者在休息时具有更高的肺液含量（平均值±SD，HFpEF：14.4±1.7%，对照组：12.8±1.7%，p=0.043），运动后肺液含量更高 (15.2± 2.0% 与 12.6±1.5%，p=0.009）。更高肺流体内容物用较低的DL相关联的_CO与HFPEF受试者和肺泡-毛细血管膜电导（DM）（DL _CO: R=-0.57, p=0.022, Dm: R=-0.61, p=0.012)，但不在对照中。肺血容量未因运动而改变，且组间相似。结论 - 与对照组相比，次极量运动在 HFpEF 中引起更大的肺液积聚，并且肺液含量与 HFpEF 中的肺扩散能力和肺泡 - 毛细血管膜电导呈负相关。