title: Pulmonary rehabilitation improves heart rate variability at peak exercise, exercise capacity and health-related quality of life in chronic obstructive pulmonary disease.
abstract: OBJECTIVE
  Patients with chronic obstructive pulmonary disease (COPD) appear to have impaired cardiac autonomic modulation with depressed heart rate variability (HRV). Pulmonary rehabilitation (PR) is recommended as an integral part of the management. However, the effect of PR on HRV at peak exercise remains unclear.
  
  
  METHODS
  Sixty-four patients with COPD participated in a 12-week, 2 sessions-per-week, hospital-based PR program. Baseline and post-PR status were evaluated by spirometry, HRV, health-related quality of life (HRQL, St. George's Respiratory Questionnaire, SGRQ), cardiopulmonary exercise test, respiratory muscle strength, and dyspnea Borg's scale.
  
  
  RESULTS
  After PR, there were significant improvements in the time and frequency domains of HRV with increased standard deviation of the normal R-R intervals, difference between adjacent normal R-R intervals within a given time minus one, high-frequency and decreased low-frequency, as well as concurrent improvements in HRQL, exercise capacity, dyspnea score, and respiratory muscle strength (all p < 0.05).
  
  
  CONCLUSIONS
  PR results in significant improvements in autonomic function, with concurrent improvements in HRQL and exercise capacity.
authors.affiliation: Department of Cardiology, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan; School of Medicine, Tzu Chi University, Hualien, Taiwan.
authors.forename: Shih-Tsung
authors.initials: ST
authors.lastname: Cheng
authors.affiliation: School of Medicine, Tzu Chi University, Hualien, Taiwan; Division of Pulmonary Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan.
authors.forename: Yao-Kuang
authors.initials: YK
authors.lastname: Wu
authors.affiliation: School of Medicine, Tzu Chi University, Hualien, Taiwan; Division of Pulmonary Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan.
authors.forename: Mei-Chen
authors.initials: MC
authors.lastname: Yang
authors.affiliation: School of Medicine, Tzu Chi University, Hualien, Taiwan; Division of Pulmonary Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan.
authors.forename: Chun-Yao
authors.initials: CY
authors.lastname: Huang
authors.affiliation: Department of Nursing, Cardinal Tien College of Healthcare & Management, Taipei, Taiwan.
authors.forename: Hui-Chuan
authors.initials: HC
authors.lastname: Huang
authors.affiliation: Department of Respiratory Therapy, Hsiao Chung Cheng Hospital, Taipei, Taiwan.
authors.forename: Wen-Hua
authors.initials: WH
authors.lastname: Chu
authors.affiliation: School of Medicine, Tzu Chi University, Hualien, Taiwan; Division of Pulmonary Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei, Taiwan. Electronic address: bluescopy@yahoo.com.tw.
authors.forename: Chou-Chin
authors.initials: CC
authors.lastname: Lan
mesh_terms: D000368:Aged; D004417:Dyspnea / Q000175:diagnosis / Q000209:etiology; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology / Q000534:rehabilitation*; D011788:Quality of Life; D013147:Spirometry; D011795:Surveys and Questionnaires
keywords: Chronic obstructive pulmonary disease; Exercise capacity; Health-related quality of life; Heart rate variability; Pulmonary rehabilitation