1. Pulmonary Function and Clinical Exercise Physiology Unit, Division of Respirology, and
2. Division of Cardiology, Federal University of Sao Paulo, Sao Paulo, Brazil
3. Division of Respirology, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
4. Medical Imaging Research Laboratory, Federal University of Health Sciences, Porto Alegre, Brazil; and
5. Respiratory Investigation Unit, Queen’s University, Kingston, Ontario, Canada