title: Effect of physical training on ventilatory patterns during exercise in patients with heart disease.
abstract: BACKGROUND
  Exercise training is known to improve the shortness of breath experienced by patients with heart disease when the ventilatory pattern becomes abnormal during exercise. However, the precise relationship between breathing patterns and the effect of exercise training has not been elucidated to date. We evaluated the relationship between the effect of exercise training on exercise tolerance and the amelioration of the ventilatory response during exercise in such patients.
  
  
  RESULTS
  Patients with heart disease (n=170) underwent cardiopulmonary exercise testing twice (pre- and postexercise training for 3-6 months). They were divided into the exercise training group (Group E, n=123) and control group (Group C, n=47). Regression line relating tidal volume to respiratory rate (TV-RR slope) during a ramp protocol below the inflection point was regarded as an indicator of rapid ventilation. Tidal volume after the inflection point was regarded as an indicator of shallow ventilation (TV at plateau). The TV-RR slope and TV at plateau improved after exercise training from 94.8±45.9 to 129.9±69.5 (p<0.001) and from 1473.6±321.9mL to 1673.2±355.1mL (p<0.001), respectively, in Group E. In contrast, no improvement was evident in Group C. In total, %anaerobic threshold (%AT) [AT improving ratio=(post-AT-pre-AT)/pre-AT×100] was positively correlated with both %TV-RR slope [TV-RR slope improving ratio=(post-TV-RR slope-pre-TV-RR slope)/pre-TV-RR slope×100] (r=0.60) and %TV at plateau [TV at plateau improving ratio=(post-TV at plateau-pre-TV at plateau)/pre-TV at plateau×100] (r=0.51).
  
  
  CONCLUSIONS
  Exercise training improved the rapidness and depth of breathing during exercise. Therefore, improvement of abnormal ventilatory patterns is correlated with exercise tolerance.
authors.affiliation: Department of Medicine and Biological Science, Graduate School of Medicine, Gunma University, Gunma, Japan. Electronic address: m10702029@gunma-u.ac.jp.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Taguchi
authors.affiliation: Gunma Prefectural Cardiovascular Center, Gunma, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Adachi
authors.affiliation: Gunma Prefectural Cardiovascular Center, Gunma, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hoshizaki
authors.affiliation: Gunma Prefectural Cardiovascular Center, Gunma, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Oshima
authors.affiliation: Department of Medicine and Biological Science, Graduate School of Medicine, Gunma University, Gunma, Japan.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kurabayashi
mesh_terms: D000368:Aged; D015308:Anaerobic Threshold; D005080:Exercise Test; D005081:Exercise Therapy / Q000706:statistics & numerical data*; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006331:Heart Diseases / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D064797:Physical Conditioning, Human; D012123:Pulmonary Ventilation / Q000502:physiology*; D012119:Respiration; D056152:Respiratory Rate; D013990:Tidal Volume
keywords: Cardiac rehabilitation; Heart disease; Rapid and shallow breathing; Respiratory pattern