确定射血分数保留的心力衰竭患者外周运动受限表型的机制。
Identifying the Mechanisms of a Peripherally Limited Exercise Phenotype in Patients With Heart Failure With Preserved Ejection Fraction.
作者信息
Skow Rachel J, Sarma Satyam, MacNamara James P, Bartlett Miles F, Wakeham Denis J, Martin Zachary T, Samels Mitchel, Nandadeva Damsara, Brazile Tiffany L, Ren Jimin, Fu Qi, Babb Tony G, Balmain Bryce N, Nelson Michael D, Hynan Linda S, Levine Benjamin D, Fadel Paul J, Haykowsky Mark J, Hearon Christopher M
机构信息
Department of Kinesiology, University of Texas at Arlington (R.J.S., M.F.B., Z.T.M., D.N., M.D.N., P.J.F.).
Faculty of Nursing, College of Health Sciences, University of Alberta, Edmonton, AB, Canada (R.J.S., M.J.H.).
出版信息
Circ Heart Fail. 2024 Aug;17(8):e011693. doi: 10.1161/CIRCHEARTFAILURE.123.011693. Epub 2024 Jul 25.
BACKGROUND
We identified peripherally limited patients using cardiopulmonary exercise testing and measured skeletal muscle oxygen transport and utilization during invasive single leg exercise testing to identify the mechanisms of the peripheral limitation.
METHODS
Forty-five patients with heart failure with preserved ejection fraction (70±7 years, 27 females) completed seated upright cardiopulmonary exercise testing and were defined as having a (1) peripheral limitation to exercise if cardiac output/oxygen consumption (VO) was elevated (≥6) or 5 to 6 with a stroke volume reserve >50% (n=31) or (2) a central limitation to exercise if cardiac output/VO slope was ≤5 or 5 to 6 with stroke volume reserve <50% (n=14). Single leg knee extension exercise was used to quantify peak leg blood flow (Doppler ultrasound), arterial-to-venous oxygen content difference (femoral venous catheter), leg VO, and muscle oxygen diffusive conductance. In a subset of participants (n=36), phosphocreatine recovery time was measured by magnetic resonance spectroscopy to determine skeletal muscle oxidative capacity.
RESULTS
Peak VO during cardiopulmonary exercise testing was not different between groups (central: 13.9±5.7 versus peripheral: 12.0±3.1 mL/min per kg; =0.135); however, the peripheral group had a lower peak arterial-to-venous oxygen content difference (central: 13.5±2.0 versus peripheral: 11.1±1.6 mLO/dL blood; <0.001). During single leg knee extension, there was no difference in peak leg VO (=0.306), but the peripherally limited group had greater blood flow/VO ratio (=0.024), lower arterial-to-venous oxygen content difference (central: 12.3±2.5 versus peripheral: 10.3±2.2 mLO/dL blood; =0.013), and lower muscle oxygen diffusive conductance (=0.021). A difference in magnetic resonance spectroscopy-derived phosphocreatine recovery time was not detected (=0.199).
CONCLUSIONS
Peripherally limited patients with heart failure with preserved ejection fraction identified by cardiopulmonary exercise testing have impairments in oxygen transport and utilization at the level of the skeletal muscle quantified by invasive knee extension exercise testing, which includes an increased blood flow/V̇O ratio and poor muscle diffusive capacity.
REGISTRATION
URL: https://www.clinicaltrials.gov; Unique identifier: NCT04068844.
背景
我们通过心肺运动试验识别出外周受限的患者，并在有创单腿运动试验期间测量骨骼肌氧运输和利用情况，以确定外周受限的机制。
方法
45例射血分数保留的心力衰竭患者（年龄70±7岁，女性27例）完成坐位直立心肺运动试验，若心输出量/氧耗量（VO）升高（≥6）或为5至6且每搏量储备>50%，则定义为（1）运动外周受限（n = 31）；若心输出量/VO斜率≤5或为5至6且每搏量储备<50%，则定义为（2）运动中心受限（n = 14）。采用单腿膝关节伸展运动来量化峰值腿部血流量（多普勒超声）、动静脉氧含量差（股静脉导管）、腿部VO和肌肉氧扩散传导率。在一部分参与者（n = 36）中，通过磁共振波谱测量磷酸肌酸恢复时间，以确定骨骼肌氧化能力。
结果
心肺运动试验期间的峰值VO在两组之间无差异（中心受限组：13.9±5.7与外周受限组：12.0±3.1 mL/min per kg；P = 0.135）；然而，外周受限组的峰值动静脉氧含量差较低（中心受限组：13.5±2.0与外周受限组：11.1±1.6 mLO/dL血液；P<0.001）。在单腿膝关节伸展过程中，峰值腿部VO无差异（P = 0.306），但外周受限组的血流量/VO比值更高（P = 0.024），动静脉氧含量差更低（中心受限组：12.3±2.5与外周受限组：10.3±2.2 mLO/dL血液；P = 0.013），肌肉氧扩散传导率更低（P = 0.021）。未检测到磁共振波谱衍生的磷酸肌酸恢复时间存在差异（P = 0.199）。
结论
通过心肺运动试验识别出的射血分数保留的心力衰竭外周受限患者，在有创膝关节伸展运动试验量化的骨骼肌水平上存在氧运输和利用受损情况，包括血流量/V̇O比值增加和肌肉扩散能力差。
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