Magnusson G, Kaijser L, Rong H, Isberg B, Sylvén C, Saltin B
Department of Physiology and Pharmacology, Karolinska Institute, Huddinge Hospital, Sweden.
Clin Physiol. 1996 Mar;16(2):183-95. doi: 10.1111/j.1475-097x.1996.tb00567.x.
The knee extensor and the whole-body exercise capacities were measured in 11 chronic heart failure (CHF) patients and 11 healthy age- and sex-matched controls, and were related to ejection fraction and to biochemical and histochemical markers of the musculature. The CHF patients had a 39% lower maximal oxygen uptake measured on an ergometer cycle than the healthy controls (1.54 +/- 0.57 vs. 2.51 +/- 0.70 1 min-1, P < 0.001). The low exercise capacity was markedly related to the ejection fraction (r = 0.77, P < 0.001). The maximal strength of m. quadriceps femoris was 15% lower in the CHF patients than in the controls (P < 0.05). The cross-sectional area (CSA) of m. quadriceps femoris explained 55% (r = 0.74, P < 0.001) of the difference in strength between both groups. The endurance capacity of m. quadriceps femoris was 30% lower in CHF patients than in controls, partly as a result of the 25% lower capillary density (P < 0.05) and the 27% lower aerobic enzyme capacity (P < 0.05), as estimated by the citrate synthase activity, in the CHF patients. The citrate synthase activity correlated with the maximal oxygen uptake (r = 0.61, P < 0.05). Moreover, the ejection fraction, together with the CSA of m. quadriceps femoris, explained 75% (r = 0.86%, P < 0.01) of the difference in maximal oxygen uptake between CHF patients and controls. These results demonstrate that CHF patients have both a lower local and a lower whole-body work capacity than healthy controls. This is a function of a smaller leg muscle mass and a lower capillary density and mitochondrial enzyme capacity in the CHF patients; however, a lowered pump capacity of the heart is the factor which limits the exercise capacity the most.
对11名慢性心力衰竭（CHF）患者和11名年龄及性别匹配的健康对照者进行了膝伸肌和全身运动能力测量，并将其与射血分数以及肌肉组织的生化和组织化学标志物相关联。CHF患者在测力计上测得的最大摄氧量比健康对照者低39%（1.54±0.57对2.51±0.70 l min⁻¹，P<0.001）。低运动能力与射血分数显著相关（r = 0.77，P<0.001）。CHF患者股四头肌的最大力量比对照组低15%（P<0.05）。股四头肌的横截面积（CSA）解释了两组之间力量差异的55%（r = 0.74，P<0.001）。CHF患者股四头肌的耐力比对照组低30%，部分原因是CHF患者的毛细血管密度低25%（P<0.05），以及通过柠檬酸合酶活性估计的有氧酶能力低27%（P<0.05）。柠檬酸合酶活性与最大摄氧量相关（r = 0.61，P<0.05）。此外，射血分数与股四头肌的CSA共同解释了CHF患者和对照组之间最大摄氧量差异的75%（r = 0.86%，P<0.01）。这些结果表明，CHF患者的局部和全身工作能力均低于健康对照者。这是CHF患者腿部肌肉质量较小、毛细血管密度较低和线粒体酶能力较低的结果；然而，心脏泵血能力降低是限制运动能力的最主要因素。
