title: [Is there a disassociation of ventilatory and electromyographic thresholds in patients with heart disease during a graded cycling exercise?]
abstract: Exercise prescription was generally based on the determination of ventilatory thresholds (VT1, VT2) during cardiopulmonary exercise testing (CPX). Changes in surface electromyographic activity (EMGth1, EMGth2) were also related to VT1and VT2in healthy subjects.
  
  
  OBJECTIVE
  To observe the occurrence of EMGth1and EMGth2and whether these events accompany VT1and VT2during CPX in cardiac patients (CP).
  
  
  METHODS
  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. VT1was determined as the breakpoint in the curve of carbon dioxide output against oxygen uptake plot (V-slope method). VT2was 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. EMGth1and EMGth2were defined as the first and the second breakpoints in the rms-EMG-power output relationship.
  
  
  RESULTS
  Peak values of oxygen uptake (16.3±4.6mL·min-1·kg-1) and heart rate (106.7±13.8bpm) were reached at 112.9±38.5w (PMT). VT1and VT2occurred 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, EMGth1at 68.0±24.7w and EMGth2at 88.5±30.1w, i.e. 60.0±7.6 and 78.6±5.0% of PMT. EMGth1occurred significantly before VT1(P=0.004, small effect size). No significant difference was observed between EMGth2and VT2(P=0.13, small effect size).
  
  
  CONCLUSIONS
  The EMGth1occurrence before VT1suggested a role of skeletal muscle conditioning on ventilatory responses, which should be taken into account in cardiac rehabilitation program prescription.
authors.affiliation: 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. Electronic address: pierre-marie.lepretre@u-picardie.fr.
authors.forename: P-M
authors.initials: PM
authors.lastname: Leprêtre
authors.affiliation: 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.
authors.forename: M
authors.initials: M
authors.lastname: Ghannem
authors.affiliation: Laboratoire périnatalité et risques toxiques PERITOX - UMI_01, unité mixte INERIS, CHU Amiens-Picardie, 80480 Salouël, France; Institut d'ingénierie de la santé (2IS), UFR de médecine, université de Picardie-Jules-Verne, 80000 Amiens, France.
authors.forename: S
authors.initials: S
authors.lastname: Delanaud
authors.affiliation: Centre de réadaptation cardiaque Léopold-Bellan, château d'Ollencourt, 60170 Tracy-Le-Mont, France.
authors.forename: T
authors.initials: T
authors.lastname: Porcher
authors.affiliation: Institut d'ingénierie de la santé (2IS), UFR de médecine, université de Picardie-Jules-Verne, 80000 Amiens, France.
authors.forename: A
authors.initials: A
authors.lastname: Barnabé
authors.affiliation: Centre de réadaptation cardiaque Léopold-Bellan, château d'Ollencourt, 60170 Tracy-Le-Mont, France; Institut d'ingénierie de la santé (2IS), UFR de médecine, université de Picardie-Jules-Verne, 80000 Amiens, France.
authors.forename: L
authors.initials: L
authors.lastname: Gaillard
authors.affiliation: Centre de réadaptation cardiaque Léopold-Bellan, château d'Ollencourt, 60170 Tracy-Le-Mont, France.
authors.forename: N
authors.initials: N
authors.lastname: Jaunet
authors.affiliation: 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; Institut d'ingénierie de la santé (2IS), UFR de médecine, université de Picardie-Jules-Verne, 80000 Amiens, France.
authors.forename: T
authors.initials: T
authors.lastname: Weissland
mesh_terms: D000368:Aged; D015308:Anaerobic Threshold / Q000502:physiology; D002245:Carbon Dioxide / Q000097:blood; D004576:Electromyography; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018763:Muscle Fatigue / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D012123:Pulmonary Ventilation / Q000502:physiology*; D052097:Quadriceps Muscle / Q000503:physiopathology
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen
keywords: Electromyography; Exercice; Exercise; Gas exchange; Seuils ventilatoires; Testing; Ventilatory threshold; Échanges gazeux; Électromyographie; Évaluation