title: Cardiopulmonary adaptation to short-term high altitude exposure in adult Fontan patients.
abstract: High altitude-related hypoxia induces pulmonary vasoconstriction. In Fontan patients without a contractile subpulmonary ventricle, an increase in pulmonary artery pressure is expected to decrease circulatory output and reduce exercise capacity. This study investigates the direct effects of short-term high altitude exposure on pulmonary blood flow (PBF) and exercise capacity in Fontan patients.
  
  
  
  16 adult Fontan patients (mean age 28±7 years, 56% female) and 14 matched controls underwent cardiopulmonary exercise testing with measurement of PBF with a gas rebreathing system at 540 m (low altitude) and at 3454 m (high altitude) within 12 weeks.
  
  
  
  PBF at rest and at exercise was higher in controls than in Fontan patients, both at low and high altitude. PBF increased twofold in Fontan patients and 2.8-fold in the control group during submaximal exercise, with no significant difference between low and high altitude (p=0.290). A reduction in peak oxygen uptake at high compared with low altitude was observed in Fontan patients (22.8±5.1 and 20.5±3.8 mL/min/kg, p<0.001) and the control group (35.0±7.4 and 29.1±6.5 mL/min/kg, p<0.001). The reduction in exercise capacity was less pronounced in Fontan patients compared with controls (9±12% vs 17±8%, p=0.005). No major adverse clinical event was observed.
  
  
  
  Short-term high altitude exposure has no negative impact on PBF and exercise capacity in Fontan patients when compared with controls, and was clinically well tolerated.
  
  
  
  NCT02237274: Results.
authors.affiliation: Department of Cardiology, Preventive Cardiology and Sports Medicine, Inselspital, University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Roger
authors.initials: R
authors.lastname: Staempfli
authors.affiliation: Department of Cardiology, Preventive Cardiology and Sports Medicine, Inselspital, University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Schmid
authors.affiliation: Department of Cardiology, Center for Congenital Heart Disease, Inselspital, University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Schenker
authors.affiliation: Department of Cardiology, Preventive Cardiology and Sports Medicine, Inselspital, University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Prisca
authors.initials: P
authors.lastname: Eser
authors.affiliation: Department of Cardiology, Preventive Cardiology and Sports Medicine, Inselspital, University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Lukas D
authors.initials: LD
authors.lastname: Trachsel
authors.affiliation: Department of Cardiology, Preventive Cardiology and Sports Medicine, Inselspital, University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Christina
authors.initials: C
authors.lastname: Deluigi
authors.affiliation: Department of Cardiology, Center for Congenital Heart Disease, Inselspital, University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Wustmann
authors.affiliation: Department of Cardiology, Center for Congenital Heart Disease, Inselspital, University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Corina
authors.initials: C
authors.lastname: Thomet
authors.affiliation: Department of Cardiology, University Heart Center, Cardiology, Zurich, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Greutmann
authors.affiliation: Department of Cardiology, University Hospital, Basel, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Tobler
authors.affiliation: Department of Cardiology, Kantonsspital, St. Gallen, Switzerland.
authors.forename: Dominik
authors.initials: D
authors.lastname: Stambach
authors.affiliation: Department of Cardiology, Preventive Cardiology and Sports Medicine, Inselspital, University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Matthias
authors.initials: M
authors.lastname: Wilhelm
authors.affiliation: Department of Cardiology, Center for Congenital Heart Disease, Inselspital, University Hospital, University of Bern, Bern, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Schwerzmann
mesh_terms: D000064:Acclimatization; D000328:Adult; D000531:Altitude; D001944:Breath Tests; D016022:Case-Control Studies; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D018729:Fontan Procedure; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D011652:Pulmonary Circulation; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult