title: Effects of exercise rehabilitation program on heart rate recovery in patients with chronic heart failure.
abstract: BACKGROUND
  Heart rate recovery (HRR1) immediately after exercise reflects parasympathetic activity, which is markedly attenuated in chronic heart failure (CHF) patients. The aim of our study was to examine both continuous and interval exercise training effects on HRR1 in these patients.
  
  
  METHODS
  The population study consisted of 29 stable CHF patients that participated at a rehabilitation program of 36 sessions, three times per week. Of the 29 patients, 24 completed the program. Patients were randomly assigned to interval {n=10 [100% peak work rate (WRp) for 30 s, alternating with rest for 30 s]} and to continuous training [n=14 (50%WRp)].
  
  
  METHODS
  All patients performed a symptom-limited cardiopulmonary exercise test on a cycle ergometer before and after the completion of the program. Measurements included peak oxygen uptake (VO2p), anaerobic threshold (AT), WRp, first degree slope of VO2 during the first minute of recovery (VO2/t-slope), chronotropic response [% chronotropic reserve (CR)=(peak HR - resting HR)x100/(220 - age - resting HR)], HRR1 (HR difference from peak exercise to one minute after).
  
  
  RESULTS
  After the completion of the rehabilitation program there was a significant increase of WRp, VO2p, AT and VO2/t-slope (by 30%, P=0.01; 6%, P=0.01; 10%, P=0.02; and 27%, P=0.03 respectively for continuous training and by 21%, P<0.05; 8%, P=0.01; 6%, P=NS; and 48%, P=0.02 respectively for interval training). However, only patients exercised under the continuous training regime had a significant increase in HRR1 (15.0+/-9.0 to 24.0+/-12 bpm; P=0.02) and CR (57+/-19 to 72+/-21%, P=0.02), in contrast with those assigned to interval training (HRR1: 21+/-11 to 21+/-8 bpm; P=NS and CR: 57+/-18 to 59+/-21%, P=NS).
  
  
  CONCLUSIONS
  Both continuous and interval exercise training program improves exercise capacity in CHF patients. However, continuous rather than interval exercise training improves early HRR1, a marker of parasympathetic activity, suggesting a greater contribution to the autonomic nervous system.
authors.affiliation: Pulmonary & Critical Care Medicine Department, Cardiopulmonary Exercise Testing and Rehabilitation Laboratory, Evgenidio Hospital, National and Kapodestrian University of Athens, Greece.
authors.forename: Stavros
authors.initials: S
authors.lastname: Dimopoulos
authors.forename: Maria
authors.initials: M
authors.lastname: Anastasiou-Nana
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Sakellariou
authors.forename: Stavros
authors.initials: S
authors.lastname: Drakos
authors.forename: Smaragdo
authors.initials: S
authors.lastname: Kapsimalakou
authors.forename: George
authors.initials: G
authors.lastname: Maroulidis
authors.forename: Petros
authors.initials: P
authors.lastname: Roditis
authors.forename: Ourania
authors.initials: O
authors.lastname: Papazachou
authors.forename: Ioannis
authors.initials: I
authors.lastname: Vogiatzis
authors.forename: Charis
authors.initials: C
authors.lastname: Roussos
authors.forename: Serafim
authors.initials: S
authors.lastname: Nanas
mesh_terms: D000328:Adult; D000368:Aged; D015308:Anaerobic Threshold; D001341:Autonomic Nervous System / Q000502:physiology*; D005081:Exercise Therapy; D005260:Female; D006333:Heart Failure / Q000503:physiopathology* / Q000534:rehabilitation; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D016896:Treatment Outcome