Greiner Andreas, Esterhammer Regina, Messner Hubert, Biebl Mathias, Mühlthaler Hannes, Fraedrich Gustav, Jaschke Werner R, Schocke Michael F H
Department of Surgery, Division of Vascular Surgery, Innsbruck Medical University, Innsbruck, Austria.
J Vasc Surg. 2006 May;43(5):978-86. doi: 10.1016/j.jvs.2006.01.020.
The treadmill exercise test is the most important examination of the functional ability of patients with intermittent claudication or leg pain during exercise, but it does not provide any metabolic information in the calf muscle. The purpose of this study was to investigate the high-energy metabolism in the calf muscle during incremental progressive plantar flexion exercise of a selected peripheral arterial disease (PAD) patient group.
Using a 1.5-T whole-body magnetic resonance scanner, 17 male patients with PAD who had 1 symptomatic and 1 asymptomatic leg and 9 healthy male controls underwent serial phosphor 31 (31P) magnetic resonance spectroscopy during incremental exercise at 2, 3, 4, and 5 W. Furthermore, magnetic resonance angiography was performed, and the ankle-brachial pressure index was determined in the patient group. The runoff resistance (ROR) was separately assessed in each patient's leg.
The symptomatic legs exhibited significantly increased phosphocreatine (PCr) time constants during the first three workload increments (2-4 W) and the recovery phase compared with the asymptomatic legs and the normal controls. Only two symptomatic legs reached the last increment at 5 W. Compared with the normal controls, the asymptomatic legs showed significantly increased PCr time constants only at 5 W. In the patient group, we detected significant correlations between the PCr time constants and the ROR, as well as the ankle-brachial pressure index. Moreover, the symptomatic legs presented significantly lower PCr levels and pH values at the end of exercise compared with the asymptomatic and control legs.
Our study shows that muscle function in PAD patients can be objectively quantified with the help of 31P magnetic resonance spectroscopy and correlates significantly with hemodynamic parameters such as ROR and ankle-brachial pressure index. Consequently, 31P magnetic resonance spectroscopy seems to be a useful method to monitor the muscle function of PAD patients for evaluation of established therapies or new therapeutic strategies during research trials.
跑步机运动试验是间歇性跛行或运动时腿痛患者功能能力的最重要检查，但它无法提供小腿肌肉的任何代谢信息。本研究的目的是调查特定外周动脉疾病（PAD）患者组在递增性渐进性跖屈运动期间小腿肌肉的高能代谢情况。
使用1.5-T全身磁共振扫描仪，对17例有一条症状性腿和一条无症状腿的男性PAD患者以及9名健康男性对照者在2、3、4和5瓦的递增运动过程中进行连续的磷31（31P）磁共振波谱分析。此外，对患者组进行磁共振血管造影，并测定踝臂压力指数。分别评估每位患者每条腿的血流阻力（ROR）。
与无症状腿和正常对照组相比，症状性腿在前三个工作负荷增量（2-4瓦）及恢复阶段的磷酸肌酸（PCr）时间常数显著增加。只有两条症状性腿达到了5瓦的最后增量。与正常对照组相比，无症状腿仅在5瓦时PCr时间常数显著增加。在患者组中，我们检测到PCr时间常数与ROR以及踝臂压力指数之间存在显著相关性。此外，与无症状腿和对照腿相比，症状性腿在运动结束时的PCr水平和pH值显著更低。
我们的研究表明，借助31P磁共振波谱可以客观地量化PAD患者的肌肉功能，并且与ROR和踝臂压力指数等血流动力学参数显著相关。因此，31P磁共振波谱似乎是一种有用的方法，可用于监测PAD患者的肌肉功能，以评估既定疗法或研究试验中的新治疗策略。
