Is parasternal intercostal EMG an accurate surrogate of respiratory neural drive and biomarker of dyspnea during cycle exercise testing?
Recent evidence suggests that surface electromyography of the parasternal intercostals (EMGpara) can be a non-invasive alternative to diaphragmatic EMG (EMGdi) for estimating neural respiratory drive (NRD) during cardiopulmonary exercise testing (CPET). The purpose of this study was to determine if non-respiratory muscles influence EMGpara by having subjects place their hands on (Hon) and off (Hoff) the handlebars during cycling-based CPET. Ten healthy adults performed an incremental cycling test until volitional exhaustion. Participants were instrumented with an esophageal electrode catheter to measure EMGdi, and surface electrodes on the 2nd intercostal space to measure EMGpara. Subjects alternated between 30s of Honand 30s Hoffduring each exercise stage. There were no differences in EMGdi across all exercise intensities. However, EMGpara was significantly greater during the Honvs. Hoffcondition at all exercise intensities (p<0.05). These results suggest that EMGpara may not be an appropriate surrogate of NRD during cycle exercise testing due to co-activation of adjacent skeletal muscles.
Centre for Heart Lung Innovation, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada; Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
Andrew H
AH
Ramsook
Centre for Heart Lung Innovation, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada; Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
Reid A
RA
Mitchell
Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
Tyson
T
Bell
Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
Suzanne
S
Calli
Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
Chris
C
Kennedy
Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
Jenny
J
Lehmann
Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada.
Matt
M
Thompson
Centre for Health Evaluation & Outcome Sciences, Providence Health Care Research Institute, University of British Columbia, St. Paul's Hospital, Vancouver, BC, Canada.
Joseph H
JH
Puyat
Centre for Heart Lung Innovation, University of British Columbia and St. Paul's Hospital, Vancouver, BC, Canada; Department of Physical Therapy, University of British Columbia, Vancouver, BC, Canada. Electronic address: jordan.guenette@hli.ubc.ca.
Jordan A
JA
Guenette
D001642:Bicycling / Q000502:physiology*; D003964:Diaphragm / Q000503:physiopathology*; D004417:Dyspnea / Q000503:physiopathology*; D004576:Electromyography; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006801:Humans; D007366:Intercostal Muscles / Q000503:physiopathology*; D008297:Male; D012119:Respiration; D055815:Young Adult
Dyspnea; Electromyography; Exercise; Respiratory muscles