title: Pulmonary hypertension and ventilation during exercise: Role of the pre-capillary component.
abstract: BACKGROUND
  Excessive exercise-induced hyperventilation and high prevalence of exercise oscillatory breathing (EOB) are present in patients with post-capillary pulmonary hypertension (PH) complicating left heart disease (LHD). Patients with pre-capillary PH have even higher hyperventilation but no EOB. We sought to determine the impact of a pre-capillary component of PH on ventilatory response to exercise in patients with PH and left heart disease.
  
  
  METHODS
  We retrospectively compared patients with idiopathic or heritable pulmonary arterial hypertension (PAH, n = 29), isolated post-capillary PH (IpcPH, n = 29), and combined post- and pre-capillary PH (CpcPH, n = 12). Diastolic pressure gradient (DPG = diastolic pulmonary artery pressure - pulmonary wedge pressure) was used to distinguish IpcPH (DPG <7 mm Hg) from CpcPH (DPG ≥7 mm Hg).
  
  
  RESULTS
  Pulmonary vascular resistance (PVR) was higher in PAH, intermediate in CpcPH, and low in IpcPH. All patients with CpcPH but 1 had PVR >3 Wood unit. Exercise-induced hyperventilation (high minute ventilation over carbon dioxide production, low end-tidal carbon dioxide) was marked in PAH, intermediate in CpcPH, and low in IpcPH (p < 0.001) and correlated with DPG and PVR. Prevalence of EOB decreased from IpcPH to CpcPH to PAH (p < 0.001).
  
  
  CONCLUSIONS
  Patients with CpcPH may have worse hemodynamics than patients with IpcPH and distinct alterations of ventilatory control, consistent with more exercise-induced hyperventilation and less EOB. This might be explained at least in part by the presence and extent of pulmonary vascular disease.
authors.affiliation: Department of Cardiology, Cliniques Universitaires de Bruxelles, Hôpital Académique Erasme, Bruxelles, Belgium; Department of Cardiovascular, Neural and Metabolic Sciences, Ospedale S. Luca IRCCS Istituto Auxologico Italiano, Milan, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Caravita
authors.affiliation: Department of Cardiovascular, Neural and Metabolic Sciences, Ospedale S. Luca IRCCS Istituto Auxologico Italiano, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Faini
authors.affiliation: Department of Cardiology, Cliniques Universitaires de Bruxelles, Hôpital Académique Erasme, Bruxelles, Belgium.
authors.forename: Gael
authors.initials: G
authors.lastname: Deboeck
authors.affiliation: Department of Cardiology, Cliniques Universitaires de Bruxelles, Hôpital Académique Erasme, Bruxelles, Belgium.
authors.forename: Antoine
authors.initials: A
authors.lastname: Bondue
authors.affiliation: Department of Cardiology, Cliniques Universitaires de Bruxelles, Hôpital Académique Erasme, Bruxelles, Belgium.
authors.forename: Robert
authors.initials: R
authors.lastname: Naeije
authors.affiliation: Department of Cardiovascular, Neural and Metabolic Sciences, Ospedale S. Luca IRCCS Istituto Auxologico Italiano, Milan, Italy; Department of Health Sciences, University of Milano-Bicocca, Milan, Italy.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Parati
authors.affiliation: Department of Cardiology, Cliniques Universitaires de Bruxelles, Hôpital Académique Erasme, Bruxelles, Belgium. Electronic address: jeanluc.vachiery@erasme.ulb.ac.be.
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Vachiéry
mesh_terms: D000328:Adult; D000368:Aged; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications* / Q000503:physiopathology*; D006985:Hyperventilation / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D011652:Pulmonary Circulation; D012189:Retrospective Studies; D014655:Vascular Resistance / Q000502:physiology*
keywords: cardiopulmonary exercise test; diastolic pressure gradient; oscillatory breathing; pulmonary hypertension; ventilation