Inspiratory muscle weakness contributes to exertional dyspnea in chronic thromboembolic pulmonary hypertension

• Published in: PloS one Vol. 13; no. 9; p. e0204072
• Main Authors: Rolim, João Victor, Ota-Arakaki, Jaquelina Sonoe, Ferreira, Eloara V M, Figliolino, Gabriela A M, Ivanaga, Ivan, Vieira, Elaine Brito, Fonseca, Angelo X C, Messina, Carolina M S, Costa, Camila Melo, Neder, J Alberto, Nery, Luiz Eduardo, Ramos, Roberta Pulcheri
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 27-09-2018; Public Library of Science (PLoS)
• Subjects: Biology and Life Sciences; Catheterization; Dyspnea; Ergometry; Exercise; Exercise physiology; Heart; Hypertension; Influence; Laboratories; Medical diagnosis; Medical prognosis; Medicine; Medicine and Health Sciences; Muscle weakness; Muscles; Patients; Pulmonary arteries; Pulmonary embolisms; Pulmonary hypertension; Regression analysis; Respiration; Respiratory diseases; Thromboembolism; Ventilation; Ventilators; Brazil
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0204072

Determination of potentially-reversible factors contributing to exertional dyspnea remains an unmet clinical need in chronic thromboembolic pulmonary hypertension (CTEPH). Therefore, we aimed to evaluate the influence of inspiratory muscle weakness (IMW) on exercise capacity and dyspnea during effort in patients with CTEPH. We performed a prospective cross-sectional study that included thirty-nine consecutive patients with CTEPH (48 ± 15 yrs, 61% female) confirmed by right heart catheterization that underwent an incremental cardiopulmonary exercise test, 6-minute walk test and maximum inspiratory pressure (MIP) measurement. MIP < 70%pred was found in 46% of patients. On a multiple linear regression analysis, MIP was independently associated with 6MWD and [Formula: see text]. Patients with MIP < 70% presented greater [Formula: see text] than those with MIP ≥ 70%. Additionally, they also presented stronger sensations of dyspnea throughout exercise, even when adjusted for ventilation. At rest and at different levels of exercise, mean inspiratory flow (VT/TI) was significantly higher in patients with MIP < 70%. In conclusion, IMW is associated with a rapid increase of dyspnea, higher inspiratory load and poor exercise capacity in patients with CTEPH.