TY - JOUR T1 - Beta-blocker therapy nor hyperoxic breathing lowers ventilatory drive in pulmonary arterial hypertension patients JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - 4846 AU - Herman Groepenhoff AU - Jasmijn van Campen AU - Anco Boonsta AU - Anton Vonk-Noordegraaf AU - Harm Jan Bogaard Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/4846.abstract N2 - Introduction: Hypocapina at rest and during exercise is a common finding in pulmonary arterial hypertension patients (PAH). Increased dead-space ventilation, due to decreased perfusion of the lung, enhances ventilatory demand in PAH patients but does not explain hypocapnia. It has been suggested that increased sympathetic activation and hypoxemia play a role in driving ventilation in PAH.In this study we tested the hypothesises that reduced sympathetic activation by beta-blocker therapy or increased inspiratory oxygen pressure will lower ventilatory drive in patients with PAH.Methods: We measured in 14 stable PAH patients, at baseline, minute ventilation (VE), arterial carbon dioxide pressure (PaCO2), heart rate (HR) and the linear regression slope relating ventilation to carbon dioxide production during exercise (VE/VCO2). VE and HR were also measured during breathing a gas mixture with an inspiratory oxygen fraction of 40%. After three months of treatment of placebo or the beta-blocker bisoprolol (double blind cross-over study design), all measurements were repeated while breathing room air only. Mixed linear regression analysis was used to correct for confounding factors and to check for significance.Results:Δ: absolute difference , *** p < 0.0001 vs HR (paired t-test)Conclusion: Neither beta-blocker therapy nor hyperoxic gas breathing lowers ventilatory drive in PAH patients. ER -