alexa Pulmonary artery pressure limits exercise capacity at high altitude


Journal of Clinical & Experimental Cardiology

Author(s): Naeije R

Abstract Share this page

Altitude exposure is associated with decreased exercise capacity and increased pulmonary vascular resistance (PVR). Echocardiographic measurements of pulmonary haemodynamics and a cardiopulmonary exercise test were performed in 13 healthy subjects at sea level, in normoxia and during acute hypoxic breathing (1 h, 12% oxygen in nitrogen), and in 22 healthy subjects after acclimatisation to an altitude of 5,050 m. The measurements were obtained after randomisation, double-blinded to the intake of placebo or the endothelin A receptor blocker sitaxsentan (100 mg·day(-1) for 7 days). Blood and urine were sampled for renal function measurements. Normobaric as well as hypobaric hypoxia increased PVR and decreased maximum workload and oxygen uptake (V'(O(2),max)). Sitaxsentan decreased PVR in acute and chronic hypoxia (both p<0.001), and partly restored V'(O(2),max), by 30 % in acute hypoxia (p<0.001) and 10% in chronic hypoxia (p<0.05). Sitaxsentan-induced changes in PVR and V'(O(2),max) were correlated (p = 0.01). Hypoxia decreased glomerular filtration rate and free water clearance, and increased fractional sodium excretion. These indices of renal function were unaffected by sitaxsentan intake. Selective endothelin A receptor blockade with sitaxsentan improves mild pulmonary hypertension and restores exercise capacity without adverse effects on renal function in hypoxic normal subjects.

This article was published in Eur Respir J and referenced in Journal of Clinical & Experimental Cardiology

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version