Impairment of respiratory muscle function in pulmonary hypertension
Résumé
It has been suggested that impaired respiratory muscle function occurs in patients with pulmonary hypertension (PH). However, comprehensive investigation of respiratory muscle function - including the application of non-volitional tests - needed to verify impairment of respiratory muscle strength in PH-patients has yet not been performed. Respiratory muscle function was assessed in 31 PH-patients (20 female, mean pulmonary artery pressure 51±20 mmHg, median WHO-class 3.0±0.5, pulmonary arterial hypertension n=25, chronic-thrombembolic PH n=6) and in 31 control subjects (20 female) well-matched for gender, age and body-mass index. A six-minute walking test was performed to rate exercise capacity. Volitionally assessed maximal inspiratory (7.5±2.1 vs 6.2±2.8 kPa; p=0.04) and expiratory (13.3±4.2 vs 9.9±3.4 kPa; p<0.001) mouth pressures, sniff nasal (8.3±1.9 vs 6.6±2.2 kPa; p=0.002) and transdiaphragmatic (11.3±2.5 vs 8.7±2.5 kPa; p<0.001) pressures, non-volitionally assessed twitch mouth (1.46±0.43 vs 0.97±0.41 kPa; p<0.001) and transdiaphragmatic (2.08±0.55 vs 1.47±0.72 kPa; p=0.001) pressures during bilateral anterior magnetic phrenic nerve stimulation were markedly lower in PH-patients compared to control subjects. Maximal inspiratory mouth (r=0.58; p<0.001) and sniff transdiaphragmatic (r=0.43; p=0.02) pressures were correlated to six-minute walking distance in PH-patients. The present study provides strong evidence that inspiratory muscle strength is reduced in PH-patients compared to well-matched control subjects. Furthermore, six-minute walking distance is significantly linked to parameters assessing inspiratory muscle strength.
Origine : Fichiers produits par l'(les) auteur(s)
Loading...