title: Implications of exercise-induced pulmonary arterial hypertension.
abstract: OBJECTIVE
  To characterize the hemodynamic and ventilatory responses to exercise in a group of patients with unexplained dyspnea, increased risk for pulmonary arterial hypertension (PAH), and an elevated mean pulmonary artery pressure (mPAP; >30 mm Hg) on exercise.
  
  
  METHODS
  A total of 37 symptomatic patients at risk of PAH and 20 healthy controls underwent a cardiopulmonary exercise test and were assessed for quality of life (QOL). Patients had a pulmonary artery catheter in situ during the exercise test.
  
  
  RESULTS
  Seventeen subjects had exercise-induced PAH (EIPAH), which we defined as mPAP ≤ 25 mm Hg at rest, and mPAP > 30 mm Hg and pulmonary artery wedge pressure <20 mm Hg on exercise. These subjects had reduced peak exercise cardiac output (72% ± 19% predicted). Further, compared with matched controls, subjects with EIPAH had reduced peak oxygen consumption (1.2 ± 0.4 vs 1.7 ± 0.5 L · min, P < 0.05), an elevated ventilatory equivalent for carbon dioxide (41.0 ± 7.3 vs 31.0 ± 2.9, P < 0.05) and reduced end-tidal carbon dioxide tension (32.6 ± 3.6 vs 39.4 ± 2.7 mm Hg, P < 0.05) at the anaerobic threshold. These exercise abnormalities were associated with impaired QOL (P < 0.05).
  
  
  CONCLUSIONS
  Elevated pulmonary artery pressure on exercise can be associated with hemodynamic and ventilatory abnormalities typical of PAH, along with impaired exercise capacity and reduced QOL.
authors.affiliation: Advanced Lung Disease Program, Royal Perth Hospital, Perth, Australia.
authors.forename: Robin M
authors.initials: RM
authors.lastname: Fowler
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Maiorana
authors.forename: Sue C
authors.initials: SC
authors.lastname: Jenkins
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Gain
authors.forename: Gerry
authors.initials: G
authors.lastname: O'Driscoll
authors.forename: Eli
authors.initials: E
authors.lastname: Gabbay
mesh_terms: D000328:Adult; D000367:Age Factors; D002245:Carbon Dioxide / Q000378:metabolism; D002302:Cardiac Output / Q000502:physiology; D016022:Case-Control Studies; D057785:Catheters; D004417:Dyspnea / Q000209:etiology; D005080:Exercise Test / Q000009:adverse effects*; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D010101:Oxygen Consumption / Q000502:physiology; D011651:Pulmonary Artery; D012123:Pulmonary Ventilation / Q000502:physiology; D011669:Pulmonary Wedge Pressure / Q000502:physiology; D011788:Quality of Life; D014655:Vascular Resistance / Q000502:physiology
chemical_list: D002245:Carbon Dioxide