Lee Joshua F, Barrett-O'Keefe Zachary, Nelson Ashley D, Garten Ryan S, Ryan John J, Nativi-Nicolau Jose N, Richardson Russell S, Wray D Walter
Division of Geriatrics, Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States; Geriatric Research, Education, and Clinical Center, VA Medical Center, Salt Lake City, UT, United States.
Geriatric Research, Education, and Clinical Center, VA Medical Center, Salt Lake City, UT, United States; Department of Exercise & Sport Science, University of Utah, Salt Lake City, UT, United States.
Int J Cardiol. 2016 May 15;211:14-21. doi: 10.1016/j.ijcard.2016.02.139. Epub 2016 Mar 2.
Exercise intolerance is a hallmark symptom of heart failure patients with preserved ejection fraction (HFpEF), which may be related to an impaired ability to appropriately increase blood flow to the exercising muscle.
We evaluated leg blood flow (LBF, ultrasound Doppler), heart rate (HR), stroke volume (SV), cardiac output (CO), and mean arterial blood pressure (MAP, photoplethysmography) during dynamic, single leg knee-extensor (KE) exercise in HFpEF patients (n=21; 68 ± 2 yrs) and healthy controls (n=20; 71 ± 2 yrs).
HFpEF patients exhibited a marked attrition during KE exercise, with only 60% able to complete the exercise protocol. In participants who completed all exercise intensities (0-5-10-15 W; HFpEF, n=13; Controls, n=16), LBF was not different at 0 W and 5 W, but was 15-25% lower in HFpEF compared to controls at 10 W and 15 W (P<0.001). Likewise, leg vascular conductance (LVC), an index of vasodilation, was not different at 0 W and 5 W, but was 15-20% lower in HFpEF compared to controls at 10 W and 15 W (P<0.05). In contrast to these peripheral deficits, exercise-induced changes in central variables (HR, SV, CO), as well as MAP, were similar between groups.
These data reveal a marked reduction in LBF and LVC in HFpEF patients during exercise that cannot be attributed to a disease-related alteration in central hemodynamics, suggesting that impaired vasodilation in the exercising skeletal muscle vasculature may play a key role in the exercise intolerance associated with this patient population.
运动不耐受是射血分数保留的心力衰竭（HFpEF）患者的标志性症状，这可能与向运动肌肉适当增加血流的能力受损有关。
我们评估了HFpEF患者（n = 21；68±2岁）和健康对照者（n = 20；71±2岁）在进行动态单腿膝关节伸展（KE）运动期间的腿部血流（LBF，超声多普勒）、心率（HR）、每搏输出量（SV）、心输出量（CO）和平均动脉血压（MAP，光电容积脉搏波描记法）。
HFpEF患者在KE运动期间表现出明显的体力消耗，只有60%的患者能够完成运动方案。在完成所有运动强度（0 - 5 - 10 - 15瓦；HFpEF组，n = 13；对照组，n = 16）的参与者中，LBF在0瓦和5瓦时无差异，但在10瓦和15瓦时，HFpEF组比对照组低15 - 25%（P < 0.001）。同样，作为血管舒张指标的腿部血管传导率（LVC）在0瓦和5瓦时无差异，但在10瓦和15瓦时，HFpEF组比对照组低15 - 20%（P < 0.05）。与这些外周缺陷形成对比的是，运动引起的中心变量（HR、SV、CO）以及MAP的变化在两组之间相似。
这些数据显示，HFpEF患者在运动期间LBF和LVC显著降低，这不能归因于中心血流动力学的疾病相关改变，表明运动骨骼肌血管系统中血管舒张受损可能在与该患者群体相关的运动不耐受中起关键作用。
