Mancini D M, Ferraro N, Tuchler M, Chance B, Wilson J R
Department of Medicine, University of Pennsylvania, Philadelphia 19104.
Am J Cardiol. 1988 Dec 1;62(17):1234-40. doi: 10.1016/0002-9149(88)90266-4.
Patients with heart failure frequently report leg fatigue during exercise. At present, however, there is no objective method of detecting leg muscle abnormalities in such patients. To determine if phosphorus-31 nuclear magnetic resonance spectroscopy can provide such information, this technique was used to compare calf responses to stair climbing and plantarflexion in 20 patients with heart failure (peak oxygen consumption (VO2) of 13.6 +/- 5 ml/kg/min, ejection fraction 20 +/- 5%) and 9 age-matched normal subjects. Work was quantified by measuring VO2. At rest, both groups exhibited similar inorganic phosphorus to phosphocreatine (Pi/PCr) ratios (patients with heart failure 0.21 +/- 0.07, normal subjects 0.21 +/- 0.06, difference not significant) and pH levels (patients with heart failure 7.06 +/- 0.17, normal subjects 7.05 +/- 0.11, difference not significant). In both normal subjects and patients with heart failure, exercise resulted in a progressive rise in Pi/PCr as VO2 increased. However, examination of the relation of VO2 versus Pi/PCr revealed steeper slopes in patients with heart failure during both stair climbing and plantar-flexion. Neither form of exercise decreased calf pH in normal subjects. In the patients with heart failure, significant decreases in pH were noted during the highest work level of plantarflexion (pH of heart failure patients 6.86 +/- 0.20, pH of normal subjects 7.07 +/- 0.14, p less than 0.01). Metabolic recovery time was also prolonged in the patients with heart failure versus normal subjects (3.3 +/- 0.8 vs 2.1 +/- 0.5 minutes, respectively, p less than 0.002). These findings indicate that phosphorus-31 nuclear magnetic resonance provides objective evidence of leg muscle abnormalities in patients with heart failure.(ABSTRACT TRUNCATED AT 250 WORDS)
心力衰竭患者经常报告运动时腿部疲劳。然而，目前尚无检测此类患者腿部肌肉异常的客观方法。为了确定磷-31核磁共振波谱法是否能提供此类信息，该技术被用于比较20例心力衰竭患者（峰值耗氧量（VO2）为13.6±5毫升/千克/分钟，射血分数20±5%）和9名年龄匹配的正常受试者小腿对爬楼梯和跖屈的反应。通过测量VO2对工作量进行量化。静息时，两组的无机磷与磷酸肌酸（Pi/PCr）比值相似（心力衰竭患者为0.21±0.07，正常受试者为0.21±0.06，差异无统计学意义），pH值水平也相似（心力衰竭患者为7.06±0.17，正常受试者为7.05±0.11，差异无统计学意义）。在正常受试者和心力衰竭患者中，随着VO2增加，运动均导致Pi/PCr逐渐升高。然而，检查VO2与Pi/PCr的关系发现，心力衰竭患者在爬楼梯和跖屈过程中的斜率更陡。两种运动形式均未使正常受试者的小腿pH值降低。在心力衰竭患者中，在跖屈的最高工作量水平时观察到pH值显著降低（心力衰竭患者的pH值为6.86±0.20，正常受试者的pH值为7.07±0.14，p<0.01）。与正常受试者相比，心力衰竭患者的代谢恢复时间也延长（分别为3.3±0.8分钟和2.1±0.5分钟，p<0.002）。这些发现表明，磷-31核磁共振为心力衰竭患者腿部肌肉异常提供了客观证据。（摘要截短至250字）
