title: Exaggerated hypoxic pulmonary vasoconstriction without susceptibility to high altitude pulmonary edema.
abstract: BACKGROUND
  Abnormally high pulmonary artery pressure (PAP) in hypoxia due to exaggerated hypoxic pulmonary vasoconstriction (HPV) is a key factor for development of high-altitude pulmonary edema (HAPE). It was shown that about 10% of a healthy Caucasian population has an exaggerated HPV that is comparable to the response measured in HAPE-susceptible individuals. Therefore, we hypothesized that those with exaggerated HPV are HAPE-susceptible.
  
  
  RESULTS
  We screened 421 healthy Caucasians naïve to high altitude for HPV using Doppler echocardiography for assessment of systolic PAP in normobaric hypoxia (PASPHx; Po2 corresponding to 4500 m). Subjects with exaggerated HPV and matched controls were exposed to 4559 m with an identical protocol that causes HAPE in 62% of HAPE-S. Screening revealed 39 subjects with exaggerated HPV, of whom 33 (PASPHx 51±6 mmHg) ascended within 24 hours to 4559 m. Four (13%) of them developed HAPE during the 48 h-stay. This incidence is significantly lower than the recurrence rate of 62% previously observed in HAPE-S in the same setting. None of the control subjects (PASPHx 33±5 mmHg) developed HAPE.
  
  
  CONCLUSIONS
  An exaggerated HPV cannot be considered a surrogate maker for HAPE-susceptibility although excessively elevated PAP is a hallmark in HAPE, while a normal HPV appears to protect from HAPE in this study.
authors: 1 Internal Medicine VII, Sports Medicine, University Hospital Heidelberg , Germany .
authors: Christoph
authors: C
authors: Dehnert
authors: Derliz
authors: D
authors: Mereles
authors: Sebastian
authors: S
authors: Greiner
authors: Dagmar
authors: D
authors: Albers
authors: Fabian
authors: F
authors: Scheurlen
authors: Stefanie
authors: S
authors: Zügel
authors: Thomas
authors: T
authors: Böhm
authors: Peter
authors: P
authors: Vock
authors: Marco
authors: M
authors: Maggiorini
authors: Ekkehard
authors: E
authors: Grünig
authors: Peter
authors: P
authors: Bärtsch
mesh_terms: D000328:Adult; D000531:Altitude; D000532:Altitude Sickness / Q000453:epidemiology / Q000209:etiology*; D062186:Arterial Pressure; D016022:Case-Control Studies; D004198:Disease Susceptibility; D006801:Humans; D006976:Hypertension, Pulmonary / Q000453:epidemiology / Q000209:etiology*; D000860:Hypoxia / Q000150:complications*; D008168:Lung / Q000098:blood supply; D008875:Middle Aged; D011651:Pulmonary Artery / Q000503:physiopathology*; D013997:Time Factors; D014661:Vasoconstriction; D044465:White People
keywords: high-altitude pulmonary edema; hypoxia; pulmonary vasoconstriction