Felix Girard, PhD Student, FKQ
Clinical Exercise & Respiratory Physiology Laboratory, Department of Kinesiology & Physical Education, McGill University; Montreal, QC

Session Description

Exertional breathlessness is a prevalent and disabling symptom of respiratory disease; however, the neurophysiological mechanisms are unclear. My doctoral research will test the hypothesis that exertional breathlessness reflects the awareness of an inspiratory load compensating reflex that maintains ventilation during exercise by increasing (in response to respiratory mechanical loading) or decreasing (in response to respiratory mechanical unloading) inspiratory neural drive. To this end, intensity ratings of breathlessness and neural activation of the diaphragm and extra-diaphragmatic inspiratory muscles will be assessed at rest and during bicycle exercise in healthy volunteers aged 18 years: while breathing against a variety of inspiratory flow resistive or elastic loads (Study 1); while breathing room air or a low-density helium gas mixture (Study 2); and after experimentally induced diaphragm fatigue (Study 3). Anticipated findings will generate new knowledge on the mechanisms of exertional breathlessness, which may inform new and/or more effective therapeutic interventions.

Learning Objectives

At the end of this presentation, attendees will be able to:

  • Summarize the inter-relationships between ventilation, inspiratory neural drive, respiratory muscle pressure development, and breathlessness.
  • Explain how the respiratory system responds to intrinsic and extrinsic respiratory mechanical loads during exercise, and how perception of breathlessness is affected.
  • Better understand the neurophysiological mechanism of exertional breathlessness in people living with obstructive or restrictive lung health conditions.

CanMEDS Roles: Medical Expert, Scholar