Leprêtre P-M, Ghannem M, Delanaud S, Porcher T, Barnabé A, Gaillard L, Jaunet N, Weissland T
EA-3300, laboratoire « adaptations physiologiques à l'exercice et réadaptation à l'effort », UFR-STAPS, université de Picardie-Jules-Verne, campus Sud, allée Paschal-Grousset, 80025 Amiens cedex 1, France.
EA-3300, laboratoire « adaptations physiologiques à l'exercice et réadaptation à l'effort », UFR-STAPS, université de Picardie-Jules-Verne, campus Sud, allée Paschal-Grousset, 80025 Amiens cedex 1, France; Centre de réadaptation cardiaque Léopold-Bellan, château d'Ollencourt, 60170 Tracy-Le-Mont, France.
Ann Cardiol Angeiol (Paris). 2016 Nov;65(5):306-310. doi: 10.1016/j.ancard.2016.09.011. Epub 2016 Sep 30.
Exercise prescription was generally based on the determination of ventilatory thresholds (VT, VT) during cardiopulmonary exercise testing (CPX). Changes in surface electromyographic activity (EMG, EMG) were also related to VT and VT in healthy subjects.
To observe the occurrence of EMGt and EMG and whether these events accompany VT and VT during CPX in cardiac patients (CP).
Thirty-four CP (62.1±7.3years, 172.1±6.3cm, 81.3±15.3kg, BMI: 27.3±4.1) performed a cycle CPX at a 60-rpm cadence. VT was determined as the breakpoint in the curve of carbon dioxide output against oxygen uptake plot (V-slope method). VT was defined as the point at which the ratio of minute ventilation to carbon dioxide output starts to increase. The root mean square of electromyogram (rms-EMG) was on-line calculated from the real time bipolar surface electromyographic signals recorded from the vastus lateralis. EMG and EMG were defined as the first and the second breakpoints in the rms-EMG-power output relationship.
Peak values of oxygen uptake (16.3±4.6mL·min·kg) and heart rate (106.7±13.8bpm) were reached at 112.9±38.5w (PMT). VT and VT occurred at 71.1±25.9w (62.5±5.5% PMT) and 87.9±28.6w (78.0±5.1% PMT). All subjects presented two breakpoints in the rms-EMG curve, EMG at 68.0±24.7w and EMG at 88.5±30.1w, i.e. 60.0±7.6 and 78.6±5.0% of PMT. EMG occurred significantly before VT (P=0.004, small effect size). No significant difference was observed between EMG and VT (P=0.13, small effect size).
The EMG occurrence before VT suggested a role of skeletal muscle conditioning on ventilatory responses, which should be taken into account in cardiac rehabilitation program prescription.
运动处方通常基于心肺运动测试（CPX）期间通气阈值（VT1、VT2）的测定。在健康受试者中，表面肌电图活动（EMG）的变化也与VT1和VT2相关。
观察心脏病患者（CP）在CPX期间EMGt和EMG的发生情况，以及这些事件是否伴随VT1和VT2出现。
34名CP患者（年龄62.1±7.3岁，身高172.1±6.3厘米，体重81.3±15.3千克，BMI：27.3±4.1）以60转/分钟的踏频进行了一次自行车CPX测试。VT1被确定为二氧化碳输出量与摄氧量曲线（V斜率法）中的断点。VT2被定义为分钟通气量与二氧化碳输出量之比开始增加的点。肌电图均方根（rms-EMG）由从股外侧肌记录的实时双极表面肌电图信号在线计算得出。EMGt和EMG分别被定义为rms-EMG-功率输出关系中的第一个和第二个断点。
在112.9±38.5瓦（峰值运动强度，PMT）时达到摄氧量峰值（16.3±4.6毫升·分钟·千克）和心率峰值（106.7±13.8次/分钟）。VT1和VT2分别出现在71.1±25.9瓦（62.5±5.5% PMT）和87.9±28.6瓦（78.0±5.1% PMT）。所有受试者的rms-EMG曲线均出现两个断点，EMGt出现在68.0±24.7瓦，EMG出现在88.5±30.1瓦，即分别为PMT的60.0±7.6%和78.6±5.0%。EMGt显著早于VT1出现（P = 0.004，效应量小）。EMG和VT2之间未观察到显著差异（P = 0.13，效应量小）。
EMGt在VT1之前出现表明骨骼肌调节对通气反应有作用，这在心脏康复计划处方中应予以考虑。
