射血分数保留的老年心力衰竭患者运动不耐受的决定因素。
Determinants of exercise intolerance in elderly heart failure patients with preserved ejection fraction.
机构信息
Faculty of Rehabilitation Medicine, University of Alberta, Edmonton, Alberta, Canada.
出版信息
J Am Coll Cardiol. 2011 Jul 12;58(3):265-74. doi: 10.1016/j.jacc.2011.02.055.
OBJECTIVES
The purpose of this study was to determine the mechanisms responsible for reduced aerobic capacity (peak Vo(2)) in patients with heart failure with preserved ejection fraction (HFPEF).
BACKGROUND
HFPEF is the predominant form of heart failure in older persons. Exercise intolerance is the primary symptom among patients with HFPEF and a major determinant of reduced quality of life. In contrast to patients with heart failure and reduced ejection fraction, the mechanism of exercise intolerance in HFPEF is less well understood.
METHODS
Left ventricular volumes (2-dimensional echocardiography), cardiac output, Vo(2), and calculated arterial-venous oxygen content difference (A-Vo(2) Diff) were measured at rest and during incremental, exhaustive upright cycle exercise in 48 HFPEF patients (age 69 ± 6 years) and 25 healthy age-matched controls.
RESULTS
In HFPEF patients compared with healthy controls, Vo(2) was reduced at peak exercise (14.3 ± 0.5 ml·kg·min(-1) vs. 20.4 ± 0.6 ml·kg·min(-1); p < 0.0001) and was associated with a reduced peak cardiac output (6.3 ± 0.2 l·min(-1) vs. 7.6 ± 0.2 l·min(-1); p < 0.0001) and A-Vo(2) Diff (17 ± 0.4 ml·dl(-1) vs. 19 ± 0.4 ml·dl(-1), p < 0.0007). The strongest independent predictor of peak Vo(2) was the change in A-Vo(2) Diff from rest to peak exercise (A-Vo(2) Diff reserve) for both HFPEF patients (partial correlate, 0.58; standardized β coefficient, 0.66; p = 0.0002) and healthy controls (partial correlate, 0.61; standardized β coefficient, 0.41; p = 0.005).
CONCLUSIONS
Both reduced cardiac output and A-Vo(2) Diff contribute significantly to the severe exercise intolerance in elderly HFPEF patients. The finding that A-Vo(2) Diff reserve is an independent predictor of peak Vo(2) suggests that peripheral, noncardiac factors are important contributors to exercise intolerance in these patients.
目的
本研究旨在确定射血分数保留的心力衰竭（HFPEF）患者有氧能力（峰值 VO₂）降低的机制。
背景
HFPEF 是老年人心力衰竭的主要形式。运动耐量受损是 HFPEF 患者的主要症状，也是生活质量降低的主要决定因素。与射血分数降低的心力衰竭患者不同，HFPEF 患者运动耐量受损的机制尚不清楚。
方法
在 48 例 HFPEF 患者（年龄 69 ± 6 岁）和 25 名年龄匹配的健康对照者中，通过二维超声心动图测量左心室容积、心输出量、VO₂ 和计算得出的动静脉氧含量差（A-Vo₂ 差），并在静息和递增性、耗竭性直立循环运动时进行测量。
结果
与健康对照组相比，HFPEF 患者的峰值运动 VO₂ 降低（14.3 ± 0.5 ml·kg·min⁻¹ 比 20.4 ± 0.6 ml·kg·min⁻¹；p < 0.0001），峰值心输出量降低（6.3 ± 0.2 l·min⁻¹ 比 7.6 ± 0.2 l·min⁻¹；p < 0.0001），A-Vo₂ 差降低（17 ± 0.4 ml·dl⁻¹ 比 19 ± 0.4 ml·dl⁻¹，p < 0.0007）。峰值 VO₂ 的最强独立预测因子是 A-Vo₂ 差从静息到峰值运动的变化（A-Vo₂ 差储备），这对 HFPEF 患者（部分相关系数，0.58；标准化 β 系数，0.66；p = 0.0002）和健康对照组（部分相关系数，0.61；标准化 β 系数，0.41；p = 0.005）均适用。
结论
心输出量和 A-Vo₂ 差降低均显著导致老年 HFPEF 患者严重的运动耐量受损。发现 A-Vo₂ 差储备是峰值 VO₂ 的独立预测因子，这表明外周非心脏因素是这些患者运动耐量受损的重要因素。
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