title: Association of an abnormal exercise heart rate recovery with pulmonary function abnormalities.
abstract: BACKGROUND
  Heart rate recovery (HRR) after exercise correlates with decreased vagal tone and mortality. Patients with COPD may have altered autonomic tone. We sought to determine the association of HRR with spirometry measures of pulmonary function.
  
  
  METHODS
  We analyzed 627 patients (mean [+/- SD] age, 58 +/- 12 years; 65% men; mean FEV(1), 2.6 +/- 0.9 L, 80 +/- 20% predicted; patients receiving inhaled beta(2) agonist therapy, 10%; patients receiving inhaled anticholinergic therapy, 3%; patients receiving inhaled steroids, 5%; patients receiving oral prednisone, 4%) who had undergone maximal exercise testing and had undergone pulmonary function tests < 1 year apart. Patients with heart failure, pacemakers, and atrial fibrillation were excluded. Abnormal HRR was defined as a fall in heart rate during the first minute after exercise of <or= 12 beats/min (<or= 18 beats/min with stress echocardiography). Patients were divided into quartiles based on FEV(1) percent predicted.
  
  
  RESULTS
  An abnormal HRR was seen in 229 patients (36%). The mean FEV(1) values broken into quartiles 1 to 4 were 54 +/- 11% predicted, 74 +/- 3% predicted, 87 +/- 4% predicted, and 106 +/- 10% predicted. In smokers and nonsmokers, a worsening FEV(1) percent predicted was associated with an abnormal HRR. In a multivariable model accounting for confounding factors including medications and functional capacity, the predictors of an abnormal HRR included FEV(1) percent predicted (adjusted odds ratio for 1 SD decrease, 1.32; 95% confidence interval, 1.07 to 1.65; p = 0.0004), impaired functional capacity, male gender, and age.
  
  
  CONCLUSIONS
  Abnormalities found on spirometry are associated with abnormal HRR, which may reflect an altered autonomic tone associated with pulmonary dysfunction, either obstructive or restrictive in nature.
authors.affiliation: Department of Cardiology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
authors.forename: Niranjan
authors.initials: N
authors.lastname: Seshadri
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Gildea
authors.forename: Kevin
authors.initials: K
authors.lastname: McCarthy
authors.forename: Claire
authors.initials: C
authors.lastname: Pothier
authors.forename: Mani S
authors.initials: MS
authors.lastname: Kavuru
authors.forename: Michael S
authors.initials: MS
authors.lastname: Lauer
mesh_terms: D001341:Autonomic Nervous System / Q000503:physiopathology; D004452:Echocardiography; D015444:Exercise; D005260:Female; D005541:Forced Expiratory Volume; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy / Q000503:physiopathology*; D013147:Spirometry