title: Exercise-based cardiac rehabilitation improves heart rate recovery in elderly patients after acute myocardial infarction.
abstract: BACKGROUND
  Heart rate recovery (HRR), defined as the fall in HR during the first minute after exercise, is a marker of vagal tone, which is a powerful predictor of mortality in patients with coronary artery disease and in older patients. Whether exercise training (ET) modifies HRR in elderly patients recovering from acute myocardial infarction (AMI) is still unknown. Therefore, this study aims at evaluating the effect of ET on HRR in elderly AMI patients.
  
  
  METHODS
  This was a prospective observational study including 268 older patients after AMI (217 men, 51 women), subdivided in two groups: Group A (n = 104), enrolled in an ET program; Group B (n = 164), discharged with generic instructions to continue physical activity. At baseline and at 3-month follow-up, all Group A and 54/164 Group B patients underwent a cardiopulmonary exercise stress test, whereas 110/164 Group B patients underwent an exercise stress test.
  
  
  RESULTS
  After completion of the ET program, in Group A we observed an improvement in oxygen consumption at peak exercise (VO2peak; from 14.7 +/- 1.3 to 17.6 +/- 1.9 mL/kg/min, p < .001), in the rate of increase of ventilation per unit of increase of carbon dioxide production (VE/VCO2slope; from 34.2 +/- 3.8 to 30.4 +/- 3.0, p < .001), and in HRR (from 13.5 +/- 3.7 to 18.7 +/- 3.5 beats/min, p < .001). The changes in VO2peak and in VE/VCO2slope after ET were correlated with the improvement of HRR (r = -0.865, p < .01; r = -0.594, p < .01, respectively). No changes in these parameters were observed in Group B patients.
  
  
  CONCLUSIONS
  In older AMI patients, ET results in HRR improvement, which was correlated to the improvement in cardiopulmonary parameters. These findings may shed additional light on the possible mechanisms of the beneficial prognostic effects of ET in this patient population.
authors.affiliation: Department of Clinical Medicine, Cardiovascular and Immunological Sciences School of Medicine, University of Naples Federico II, 80131 Naples, Italy. giallauria@libero.it
authors.forename: Francesco
authors.initials: F
authors.lastname: Giallauria
authors.forename: Rosa
authors.initials: R
authors.lastname: Lucci
authors.forename: Marco
authors.initials: M
authors.lastname: Pietrosante
authors.forename: Gaetano
authors.initials: G
authors.lastname: Gargiulo
authors.forename: Anna
authors.initials: A
authors.lastname: De Lorenzo
authors.forename: Mariantonietta
authors.initials: M
authors.lastname: D'Agostino
authors.forename: Giusto
authors.initials: G
authors.lastname: Gerundo
authors.forename: Pasquale
authors.initials: P
authors.lastname: Abete
authors.forename: Franco
authors.initials: F
authors.lastname: Rengo
authors.forename: Carlo
authors.initials: C
authors.lastname: Vigorito
mesh_terms: D000368:Aged; D005080:Exercise Test; D005081:Exercise Therapy / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000534:rehabilitation*; D011446:Prospective Studies; D016896:Treatment Outcome