title: Provoked exercise desaturation in patent foramen ovale and impact of percutaneous closure.
abstract: OBJECTIVE
  This study was designed to assess the prevalence of provoked exercise desaturation (PED) in patients with patent foramen ovale (PFO) referred for cardiovascular evaluation and to evaluate the impact of PFO closure.
  
  
  BACKGROUND
  Platypnea orthodeoxia syndrome is a rare, mechanistically obscure consequence of PFO that results in oxygen desaturation during postural changes. In our clinical experience, however, it is far less common than desaturation during exercise.
  
  
  METHODS
  This was a single-center prospective study of 50 patients with newly diagnosed PFO. Each patient underwent standardized assessment for arterial oxygen saturation with pulse oximetry during postural changes and stair climbing exercise. Provoked exercise desaturation was defined as a desaturation of at least 8% from baseline to <90%. All patients who underwent closure were reevaluated 3 months after the procedure. Those with baseline PED were similarly reassessed for desaturation at follow-up.
  
  
  RESULTS
  Mean age of the cohort was 46 ± 17 years, 74% were female, 30% had migraines, and 48% had experienced a cerebrovascular event. Seventeen patients (34%) demonstrated PED. Provoked exercise desaturation patients seemed demographically similar to non-PED patients. Ten PED patients underwent PFO closure (2 surgical, and 8 percutaneous). Drop in oxygen saturation was improved by an average of 10.1 ± 4.2% after closure (p < 0.001), and New York Heart Association functional class improved by a median of 1.5 classes (interquartile range: 0.75 to 2.00, p = 0.008).
  
  
  CONCLUSIONS
  One-third of patients referred for assessment of PFO experience oxygen desaturation during stair exercise. Closure of PFO seems to ameliorate this phenomenon and improve functional status.
authors.affiliation: University of California, San Francisco, San Francisco, California, USA.
authors.forename: Ganesh P
authors.initials: GP
authors.lastname: Devendra
authors.forename: Ajinkya A
authors.initials: AA
authors.lastname: Rane
authors.forename: Richard A
authors.initials: RA
authors.lastname: Krasuski
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D006328:Cardiac Catheterization / Q000295:instrumentation; D016009:Chi-Square Distribution; D015150:Echocardiography, Doppler; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D054092:Foramen Ovale, Patent / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009820:Ohio; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011474:Prosthesis Design; D020127:Recovery of Function; D055989:Septal Occluder Device; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D015415:Biomarkers; D010100:Oxygen