RT Journal Article SR Electronic T1 Dynamic respiratory mechanics and exertional dyspnoea in pulmonary arterial hypertension JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 578 OP 587 DO 10.1183/09031936.00223611 VO 41 IS 3 A1 Laveneziana, Pierantonio A1 Garcia, Gilles A1 Joureau, Barbara A1 Nicolas-Jilwan, Fadia A1 Brahimi, Toufik A1 Laviolette, Louis A1 Sitbon, Olivier A1 Simonneau, Gérald A1 Humbert, Marc A1 Similowski, Thomas YR 2013 UL https://publications.ersnet.org//content/41/3/578.abstract AB Patients with pulmonary arterial hypertension (PAH) may exhibit reduced expiratory flows at low lung volumes, which could promote exercise-induced dynamic hyperinflation (DH). This study aimed to examine the impact of a potential exercise-related DH on the intensity of dyspnoea in patients with PAH undergoing symptom-limited incremental cardiopulmonary cycle exercise testing (CPET). 25 young (aged mean±sd 38±12 yrs) nonsmoking PAH patients with no evidence of spirometric obstruction and 10 age-matched nonsmoking healthy subjects performed CPET to the limit of tolerance. Ventilatory pattern, operating lung volumes (derived from inspiratory capacity (IC) measurements) and dyspnoea intensity (Borg scale) were assessed throughout CPET. IC decreased (i.e. DH) progressively throughout CPET in PAH patients (average 0.15 L), whereas it increased in all the healthy subjects (0.45 L). Among PAH patients, 15 (60%) exhibited a decrease in IC throughout exercise (average 0.50 L), whereas in the remaining 10 (40%) patients IC increased (average 0.36 L). Dyspnoea intensity and ventilation were greater in PAH patients than in controls at any stage of CPET, whereas inspiratory reserve volume was lower. We conclude that DH-induced mechanical constraints and excessive ventilatory demand occurred in these young nonsmoking PAH patients with no spirometric obstruction and was associated with exertional dyspnoea.