Dr. Denis O’Donnell, Queen’s University, Kingston, ON

Cardiopulmonary exercise testing is often performed to explore mechanisms of dyspnea and exercise limitation in individual patients presenting with these symptoms. Abnormalities in ventilatory mechanics often contribute to these symptoms and can be exposed by the stress of exercise even when resting pulmonary function tests are normal. This presentation will outline the main measurements of dynamic ventilatory mechanics based on ventilatory responses, breathing pattern, operating lung volumes, and flow volume loop analysis during incremental exercise testing. A number of case studies will be presented to illustrate how this simple approach can provide useful clinical information on the dynamic mechanical constraints on ventilation that might exist in symptomatic patients. The main objective is to enlighten the interpreter as to the major physiological contributors to exercise intolerance in individual patients.

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

  • Understand the value of operating lung volumes, breathing pattern, flow volume loops, and dyspnea ratings in non-invasive assessments of respiratory mechanics during exercise;
  • Understand the connections between abnormalities of ventilatory mechanics during exercise, exercise limitation and intolerable symptoms; and
  • Know how this approach allows refinement in the clinical evaluation of symptomatic patients with pulmonary disease beyond traditional resting pulmonary function tests.

CanMEDs Competencies addressed: