Buonocore M, Opasich C, Casale R
Department of Clinical Neurophysiology, Consiglio Nazionale Della Richerche, Salvatore Maugeri Foundation, IRCCS, Rehabilitation Institute of Montescano, Italy.
Arch Phys Med Rehabil. 1998 Jan;79(1):41-5. doi: 10.1016/s0003-9993(98)90206-4.
Patients with chronic heart failure (CHF) frequently complain of fatigue and exercise intolerance that are not directly related to the severity of cardiac failure. A not well-defined muscle function impairment is generally considered the cause of such symptoms. The frequency compression of electromyographic (EMG) signal power spectrum during isometric contractions is commonly accepted as an index of the fatigue occurring in the muscle (localized muscle fatigue).
The purpose of the study was to evaluate muscle fatigue development in a selected group of CHF patients by studying the compression of the EMG signal power spectrum. The first dorsal interosseus of the right, dominant hand was investigated at two levels of contraction: 40% and 80% of the maximal voluntary contraction (MVC).
In CHF patients there was early development of localized muscle fatigue during the high level of contraction (80% of MVC).
This study demonstrates the presence of an early development of localized muscle fatigue in CHF patients and confirms the possibility of an increased glycolytic metabolism. Moreover, the changes seem to show that muscle impairment is not limited to large muscles, but also occurs in small muscles of the hands, frequently used during daily activities. Finally, this study confirms the validity of EMG spectral analysis techniques in evaluating muscle fatigue of CHF patients, suggesting a possible use in the rehabilitation of such patients when the technique is correctly used.
慢性心力衰竭（CHF）患者经常抱怨疲劳和运动不耐受，这些症状与心力衰竭的严重程度没有直接关系。一般认为肌肉功能损害不明确是这些症状的原因。等长收缩期间肌电图（EMG）信号功率谱的频率压缩通常被认为是肌肉中发生的疲劳（局部肌肉疲劳）的指标。
本研究的目的是通过研究EMG信号功率谱的压缩来评估一组选定的CHF患者的肌肉疲劳发展情况。对右手优势手的第一背侧骨间肌在两种收缩水平下进行研究：最大自主收缩（MVC）的40%和80%。
在CHF患者中，在高水平收缩（MVC的80%）期间局部肌肉疲劳出现较早。
本研究证明了CHF患者中局部肌肉疲劳的早期发展，并证实了糖酵解代谢增加的可能性。此外，这些变化似乎表明肌肉损伤不仅限于大肌肉，也发生在日常活动中经常使用的手部小肌肉中。最后，本研究证实了EMG频谱分析技术在评估CHF患者肌肉疲劳方面的有效性，表明当该技术正确使用时，可能用于此类患者的康复治疗。
