title: Exercise-induced desaturation and electrocardiogram changes in people with severe lung disease: an exploratory investigation of 25 serial cases.
abstract: BACKGROUND
  Arterial desaturation is a commonly accepted clinical basis for discontinuing physical activity in people with chronic obstructive pulmonary disease.
  
  
  OBJECTIVE
  The purpose of this exploratory study was to examine the electrocardiograms of people with severe chronic obstructive pulmonary disease recovering from exercise-induced arterial desaturation.
  
  
  METHODS
  Subjects (n = 25) walked for 6 minutes while oxygen saturation was monitored.
  
  
  METHODS
  When the Spo2 decreased below 90%, subjects were asked to sit and rest while the electrocardiograms were recorded. For all patients, Spo2 decreased 11.6% on average below baseline during walking. Four patients developed dysrhythmias during desaturation, with a mean lowest Spo2 of 85%. The Spo2 in six other patients continued to decrease below 80% despite rest, yet these patients did not develop new dysrhythmias.
  
  
  CONCLUSIONS
  Our findings suggest that a decrease in Spo2 during exercise does not necessarily correlate with cardiac rhythm.
authors.affiliation: Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong.
authors.forename: Alice Y M
authors.initials: AY
authors.lastname: Jones
authors.forename: Wai-Cho
authors.initials: WC
authors.lastname: Yu
authors.forename: Ngai-Shing
authors.initials: NS
authors.lastname: Mok
authors.forename: Olivia Y Y
authors.initials: OY
authors.lastname: Yeung
authors.forename: Henry C W
authors.initials: HC
authors.lastname: Cheng
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Dean
mesh_terms: D000368:Aged; D004562:Electrocardiography; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010092:Oximetry; D010100:Oxygen / Q000097:blood*; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000503:physiopathology*; D012720:Severity of Illness Index
chemical_list: D010100:Oxygen